diff --git a/editor/base/nsComposerCommands.cpp b/editor/base/nsComposerCommands.cpp
index 21cbbfb12c2b..1fdcaee387ff 100644
--- a/editor/base/nsComposerCommands.cpp
+++ b/editor/base/nsComposerCommands.cpp
@@ -94,6 +94,24 @@ nsBaseComposerCommand::SetCommandNodeState(const nsAReadableString & aCommandNam
   return uiNode->SetAttribute(NS_ConvertASCIItoUCS2("state"), inNodeState);
 }
 
+//--------------------------------------------------------------------------------------------------------------------
+PRBool
+nsBaseComposerCommand::EditingHTML(nsIEditorShell* inEditorShell)
+//--------------------------------------------------------------------------------------------------------------------
+{
+  nsXPIDLCString  mimeType;
+  inEditorShell->GetContentsMIMEType(getter_Copies(mimeType));
+  if (nsCRT::strcmp(mimeType, "text/html") != 0)
+    return PR_FALSE;
+
+  PRBool sourceMode = PR_FALSE;
+  inEditorShell->IsHTMLSourceMode(&sourceMode);
+  if (sourceMode)
+    return PR_FALSE;
+    
+  return PR_TRUE;
+}
+
 
 #ifdef XP_MAC
 #pragma mark -
@@ -119,23 +137,12 @@ nsBaseStateUpdatingCommand::IsCommandEnabled(const nsAReadableString & aCommandN
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;  
-  if (!editorShell) return NS_OK;
-  // check for plain text?
-  nsCOMPtr<nsIEditor> editor;
-  editorShell->GetEditor(getter_AddRefs(editor));
-  if (!editor) return NS_OK;
  
-  // Enable commands only if not in HTML source edit mode
-  PRBool sourceMode = PR_FALSE;
-  editorShell->IsHTMLSourceMode(&sourceMode);
-  *outCmdEnabled = !sourceMode;
-    
-  // also udpate the command state  
-  nsresult rv = UpdateCommandState(aCommandName, refCon);
-  if (NS_FAILED(rv))
+  if (editorShell && EditingHTML(editorShell))
   {
-    *outCmdEnabled = PR_FALSE;
-    return NS_OK;
+    *outCmdEnabled = PR_TRUE;
+    // also udpate the command state. 
+    UpdateCommandState(aCommandName, refCon);
   }
   
   return NS_OK;
@@ -472,7 +479,7 @@ nsRemoveListCommand::IsCommandEnabled(const nsAReadableString & aCommandName, ns
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     // It is enabled if we are in any list type
     PRBool bMixed;
@@ -515,7 +522,7 @@ nsIndentCommand::IsCommandEnabled(const nsAReadableString & aCommandName, nsISup
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -547,7 +554,7 @@ nsOutdentCommand::IsCommandEnabled(const nsAReadableString & aCommandName, nsISu
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -571,7 +578,7 @@ nsOutdentCommand::DoCommand(const nsAReadableString & aCommandName, nsISupports
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
 
   nsresult rv = NS_OK;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsAutoString indentStr; indentStr.AssignWithConversion("outdent");
     rv = editorShell->Indent(indentStr.GetUnicode());
@@ -602,7 +609,7 @@ nsMultiStateCommand::IsCommandEnabled(const nsAReadableString & aCommandName, ns
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -923,7 +930,7 @@ nsRemoveStylesCommand::IsCommandEnabled(const nsAReadableString & aCommandName,
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -968,7 +975,7 @@ nsIncreaseFontSizeCommand::IsCommandEnabled(const nsAReadableString & aCommandNa
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -1006,7 +1013,7 @@ nsDecreaseFontSizeCommand::IsCommandEnabled(const nsAReadableString & aCommandNa
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
diff --git a/editor/base/nsComposerCommands.h b/editor/base/nsComposerCommands.h
index 50948aa96006..bae9a8c690cf 100644
--- a/editor/base/nsComposerCommands.h
+++ b/editor/base/nsComposerCommands.h
@@ -59,6 +59,8 @@ protected:
   nsresult    GetCommandNodeState(const nsAReadableString & aCommandName, nsIEditorShell* editorShell, nsString& outNodeState);
   nsresult    SetCommandNodeState(const nsAReadableString & aCommandName, nsIEditorShell* editorShell, const nsString& inNodeState);
 
+  // are we in HTML edit mode (not source view or plain text editing)
+  PRBool      EditingHTML(nsIEditorShell* inEditorShell);
 };
 
 
diff --git a/editor/base/nsEditorShell.cpp b/editor/base/nsEditorShell.cpp
index efc4de68c926..7dd268d567c0 100644
--- a/editor/base/nsEditorShell.cpp
+++ b/editor/base/nsEditorShell.cpp
@@ -100,6 +100,8 @@
 #include "nsILookAndFeel.h"
 
 #include "nsIChromeRegistry.h"
+#include "nsCExternalHandlerService.h"
+#include "nsIMIMEService.h"
 
 ///////////////////////////////////////
 // Editor Includes
@@ -207,13 +209,14 @@ GetChromeElement(nsIDocShell *aShell, const char *aID, nsIDOMElement **aElement)
 // Utility to set and attribute of a UI element
 static nsresult 
 SetChromeAttribute(nsIDocShell *aShell, const char *aID, 
-                    const char *aName,  const nsString &aValue)
+                    const nsAString& aName,  const nsAString &aValue)
 {
   nsCOMPtr<nsIDOMElement> elem;
   nsresult rv = GetChromeElement(aShell, aID, getter_AddRefs(elem));
+
+  // Set the text attribute.
   if (NS_SUCCEEDED(rv) && elem)
-    // Set the text attribute.
-    rv = elem->SetAttribute( NS_ConvertASCIItoUCS2(aName), aValue);
+    rv = elem->SetAttribute(aName, aValue);
 
   return rv;
 }
@@ -254,6 +257,8 @@ nsEditorShell::nsEditorShell()
 ,  mCloseWindowWhenLoaded(PR_FALSE)
 ,  mCantEditReason(eCantEditNoReason)
 ,  mEditorType(eUninitializedEditorType)
+,  mContentMIMEType("text/html")
+,  mContentTypeKnown(PR_FALSE)
 ,  mWrapColumn(0)
 ,  mSuggestedWordIndex(0)
 ,  mDictionaryIndex(0)
@@ -436,6 +441,37 @@ nsEditorShell::ResetEditingState()
   return NS_OK;
 }
 
+
+// is this a MIME type that we support the editing of, in plain text mode?
+const char* const gSupportedTextTypes[] = {
+  "text/plain",
+  "text/css",
+  "text/rdf",
+  "text/xml",
+  "text/xsl",
+  "text/javascript",    // obsolete type
+  "application/x-javascript",
+  "text/xul",           // obsolete type
+  "application/vnd.mozilla.xul+xml",
+  NULL      // IMPORTANT! Null must be at end
+};
+
+PRBool
+nsEditorShell::IsSupportedTextType(const char* aMIMEType)
+{
+  PRInt32   i = 0;
+  
+  while (gSupportedTextTypes[i])
+  {
+    if (nsCRT::strcmp(gSupportedTextTypes[i], aMIMEType) == 0)
+      return PR_TRUE;
+  
+    i ++;
+  }
+  
+  return PR_FALSE;
+}
+
 nsresult    
 nsEditorShell::PrepareDocumentForEditing(nsIDOMWindow* aDOMWindow, nsIURI *aUrl)
 {
@@ -884,6 +920,21 @@ nsEditorShell::GetEditorType(PRUnichar **_retval)
   return NS_OK;
 }
 
+/* attribute string contentsMIMEType; */
+NS_IMETHODIMP
+nsEditorShell::GetContentsMIMEType(char * *aContentsMIMEType)
+{
+  NS_ENSURE_ARG_POINTER(aContentsMIMEType);
+  *aContentsMIMEType = mContentMIMEType.ToNewCString();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsEditorShell::SetContentsMIMEType(const char * aContentsMIMEType)
+{
+  mContentMIMEType.Assign(aContentsMIMEType ? aContentsMIMEType : "");
+  return NS_OK;
+}
 
 nsresult
 nsEditorShell::InstantiateEditor(nsIDOMDocument *aDoc, nsIPresShell *aPresShell)
@@ -895,58 +946,66 @@ nsEditorShell::InstantiateEditor(nsIDOMDocument *aDoc, nsIPresShell *aPresShell)
   if (mEditor)
     return NS_ERROR_ALREADY_INITIALIZED;
 
-  nsresult err = NS_OK;
+  nsresult rv = NS_OK;
   
   nsCOMPtr<nsIEditor> editor;
-  err = nsComponentManager::CreateInstance(kHTMLEditorCID, nsnull, NS_GET_IID(nsIEditor), getter_AddRefs(editor));
-  if(!editor)
-    err = NS_ERROR_OUT_OF_MEMORY;
+  rv = nsComponentManager::CreateInstance(kHTMLEditorCID, nsnull, NS_GET_IID(nsIEditor), getter_AddRefs(editor));
+  if (NS_FAILED(rv)) return rv;
+
   nsCOMPtr<nsISelectionController> selCon = do_QueryInterface(aPresShell);
   
-  if (NS_SUCCEEDED(err))
+  if (mEditorTypeString.EqualsWithConversion("text"))
   {
-    if (mEditorTypeString.EqualsWithConversion("text"))
+    PRInt16 flags = nsIPlaintextEditor::eEditorPlaintextMask | nsIPlaintextEditor::eEditorEnableWrapHackMask;
+    if (mMailCompose) flags |= nsIPlaintextEditor::eEditorMailMask;
+    rv = editor->Init(aDoc, aPresShell, nsnull, selCon, flags);
+    mEditorType = ePlainTextEditorType;
+  }
+  else if (mEditorTypeString.EqualsWithConversion("html") || mEditorTypeString.IsEmpty())  // empty string default to HTML editor
+  {
+    PRUint32    editorFlags = 0;
+    EEditorType editorType  = eHTMLTextEditorType;
+    
+    // if the MIME type of the docment we are editing is text/plain, make a text editor
+    if (IsSupportedTextType(mContentMIMEType))
     {
-      PRInt16 flags = nsIPlaintextEditor::eEditorPlaintextMask | nsIPlaintextEditor::eEditorEnableWrapHackMask;
-      if (mMailCompose) flags |= nsIPlaintextEditor::eEditorMailMask;
-      err = editor->Init(aDoc, aPresShell, nsnull, selCon, flags);
-      mEditorType = ePlainTextEditorType;
+      editorFlags = nsIPlaintextEditor::eEditorPlaintextMask;
+      editorType  = ePlainTextEditorType;
     }
-    else if (mEditorTypeString.EqualsWithConversion("html") || mEditorTypeString.IsEmpty())  // empty string default to HTML editor
-    {
-      err = editor->Init(aDoc, aPresShell, nsnull, selCon, 0);
-      mEditorType = eHTMLTextEditorType;
-    }
-    else if (mEditorTypeString.EqualsWithConversion("htmlmail"))  //  HTML editor with special mail rules
-    {
-      err = editor->Init(aDoc, aPresShell, nsnull, selCon, nsIPlaintextEditor::eEditorMailMask);
-      mEditorType = eHTMLTextEditorType;
-    }
-    else
-    {
-      err = NS_ERROR_INVALID_ARG;    // this is not an editor we know about
+    
+    rv = editor->Init(aDoc, aPresShell, nsnull, selCon, editorFlags);
+    mEditorType = editorType;
+  }
+  else if (mEditorTypeString.EqualsWithConversion("htmlmail"))  //  HTML editor with special mail rules
+  {
+    rv = editor->Init(aDoc, aPresShell, nsnull, selCon, nsIPlaintextEditor::eEditorMailMask);
+    mEditorType = eHTMLTextEditorType;
+  }
+  else
+  {
+    rv = NS_ERROR_INVALID_ARG;    // this is not an editor we know about
 #if DEBUG
-      nsAutoString  errorMsg; errorMsg.AssignWithConversion("Failed to init editor. Unknown editor type \"");
-      errorMsg += mEditorTypeString;
-      errorMsg.AppendWithConversion("\"\n");
-      char  *errorMsgCString = errorMsg.ToNewCString();
-         NS_WARNING(errorMsgCString);
-         nsCRT::free(errorMsgCString);
+    nsAutoString  errorMsg; errorMsg.AssignWithConversion("Failed to init editor. Unknown editor type \"");
+    errorMsg += mEditorTypeString;
+    errorMsg.AppendWithConversion("\"\n");
+    char  *errorMsgCString = errorMsg.ToNewCString();
+    NS_WARNING(errorMsgCString);
+    nsCRT::free(errorMsgCString);
 #endif
-    }
+  }
 
     // disable the preference style sheet so we can override colors
-    if (NS_SUCCEEDED(err)) {
-      err = aPresShell->EnablePrefStyleRules(PR_FALSE,0);
-    }
+  if (NS_SUCCEEDED(rv))
+  {
+    rv = aPresShell->EnablePrefStyleRules(PR_FALSE,0);
+  }
 
-    if (NS_SUCCEEDED(err) && editor)
-    {
-      mEditor = do_QueryInterface(editor);    // this does the addref that is the owning reference
-    }
+  if (NS_SUCCEEDED(rv) && editor)
+  {
+    mEditor = do_QueryInterface(editor);    // this does the addref that is the owning reference
   }
     
-  return err;
+  return rv;
 }
 
 
@@ -1688,6 +1747,27 @@ nsEditorShell::CheckOpenWindowForURLMatch(const PRUnichar* inFileURL, nsIDOMWind
   return NS_OK;
 }
 
+// helper function
+static nsresult GetExtensionForMIMEType(const char* inMIMEType, nsACString& outExtension)
+{
+  nsresult  rv;
+  nsCOMPtr<nsIMIMEService> mimeService = do_GetService(NS_MIMESERVICE_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return rv;
+  
+  nsCOMPtr<nsIMIMEInfo>   mimeInfo;
+  rv = mimeService->GetFromMIMEType(inMIMEType, getter_AddRefs(mimeInfo));
+  if (NS_FAILED(rv)) return rv;
+
+  nsXPIDLCString  fileExtension;
+  rv = mimeInfo->FirstExtension(getter_Copies(fileExtension));
+  if (NS_FAILED(rv)) return rv;
+  
+  outExtension.Assign(fileExtension);
+
+  return NS_OK;
+}
+
+
 NS_IMETHODIMP 
 nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* aMimeType, PRBool *_retval)
 {
@@ -1696,13 +1776,20 @@ nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* a
 
   NS_ENSURE_ARG_POINTER((aMimeType));
 
-  nsAutoString mimeType(aMimeType);
-  PRBool saveAsText = mimeType.EqualsWithConversion("text/plain");
+  nsCAutoString mimeTypeCStr; mimeTypeCStr.AssignWithConversion(aMimeType);
+  PRBool saveAsText = IsSupportedTextType(mimeTypeCStr);
 
   // Currently, we only understand plain text and html
-  if (!mimeType.EqualsWithConversion("text/html") && !saveAsText)
+  if (!mimeTypeCStr.Equals("text/html") && !saveAsText)
     return NS_ERROR_FAILURE;
 
+  nsAutoString    mimeType(aMimeType);
+  
+  // if we're saving as text, force the text/plain MIME type (because we use this
+  // to get a content serializer on save)
+  if (saveAsText)
+    mimeType.Assign(NS_LITERAL_STRING("text/plain").get());
+  
   switch (mEditorType)
   {
     case ePlainTextEditorType:
@@ -1858,11 +1945,12 @@ nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* a
                 title.ReplaceChar(" .\\/@:", (PRUnichar)'_');
               }
 
+              // get the correct extension from the MIME type here
               fileName = title;
-              if (saveAsText)
-                fileName.AppendWithConversion(".txt");
-              else
-                fileName.AppendWithConversion(".html");
+              nsCAutoString fileExt(saveAsText ? "txt" : "html");
+              GetExtensionForMIMEType(mimeTypeCStr.get(), fileExt);
+              fileName.Append(PRUnichar('.'));
+              fileName.AppendWithConversion(fileExt);
             } 
             else  // have a file spec
             {
@@ -1881,9 +1969,12 @@ nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* a
                   index = fileName.RFind(".shtml", PR_TRUE);
                 if (index > 0)
                 {
+                  nsCAutoString fileExt("txt");
+                  GetExtensionForMIMEType(mimeTypeCStr.get(), fileExt);
+
                   // Truncate after "." and append "txt" extension
                   fileName.SetLength(index+1);
-                  fileName.AppendWithConversion("txt");
+                  fileName.AppendWithConversion(fileExt);
                 }
               }
 
@@ -4934,6 +5025,8 @@ nsEditorShell::OnStateChange(nsIWebProgress *aProgress,
                              PRInt32 aStateFlags,
                              nsresult aStatus)
 {
+  nsresult    rv = NS_OK;
+  
   //
   // A Request has started...
   //
@@ -4942,7 +5035,8 @@ nsEditorShell::OnStateChange(nsIWebProgress *aProgress,
     // Page level notification...
     if (aStateFlags & nsIWebProgressListener::STATE_IS_NETWORK)
     {
-      StartPageLoad();
+      nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+      StartPageLoad(channel);
     }
     // Document level notification...
     if (aStateFlags & nsIWebProgressListener::STATE_IS_DOCUMENT)
@@ -5013,12 +5107,36 @@ nsEditorShell::OnSecurityChange(nsIWebProgress *aWebProgress,
   return NS_OK;
 }
 
-nsresult nsEditorShell::StartPageLoad()
+nsresult nsEditorShell::StartPageLoad(nsIChannel *aChannel)
 {
+  nsXPIDLCString  contentType;
+  aChannel->GetContentType(getter_Copies(contentType));
+  
+  // save the original MIME type; we'll use it later
+  mContentMIMEType.Assign(contentType.get() ? contentType : "");
+  
+  if (nsCRT::strcmp(contentType, "text/html") == 0)
+  {
+    // fine, do nothing
+    mContentTypeKnown = PR_TRUE;
+  }
+  else if (IsSupportedTextType(contentType))
+  {
+    // set the mime type to text/plain so that it renders as text
+    aChannel->SetContentType("text/plain");
+    mContentTypeKnown = PR_TRUE;
+  }
+  else
+  {
+    // we don't know what this is yet. It might be HTML loaded from 
+    // a directory URL (http://www.foo.com/). We'll know the real
+    // MIME type later.
+    mContentTypeKnown = PR_FALSE;
+  }
+
   // Start the throbber
   // TODO: We should also start/stop it for saving and publishing?
-  SetChromeAttribute( mDocShell, "Editor:Throbber", "busy", 
-                      NS_ConvertASCIItoUCS2("true") );
+  SetChromeAttribute( mDocShell, "Editor:Throbber", NS_LITERAL_STRING("busy"), NS_LITERAL_STRING("true") );
 
   // set up a parser observer
   if (!mParserObserver)
@@ -5029,6 +5147,7 @@ nsresult nsEditorShell::StartPageLoad()
     }
     NS_ADDREF(mParserObserver);
     mParserObserver->RegisterTagToWatch("FRAMESET");
+    mParserObserver->RegisterTagToWatch("IFRAME");
     mParserObserver->Start();
   }
 
@@ -5048,12 +5167,31 @@ nsresult nsEditorShell::EndPageLoad(nsIDOMWindow *aDOMWindow,
     NS_RELEASE(mParserObserver);
   }
 
-  SetChromeAttribute( mDocShell, "Editor:Throbber", "busy", 
-                      NS_ConvertASCIItoUCS2("false") );
+  SetChromeAttribute( mDocShell, "Editor:Throbber", NS_LITERAL_STRING("busy"), NS_LITERAL_STRING("false") );
+
+  // Is this a MIME type we can handle?
+  if (aChannel)
+  {
+    // if we didn't get the content-type at the start of the load, get it now
+    if (!mContentTypeKnown)
+    {
+      nsXPIDLCString  contentType;
+      aChannel->GetContentType(getter_Copies(contentType));
+
+      if (contentType.get())
+        mContentMIMEType.Assign(contentType);
+    }
+  }    
+    
+  if ( !mContentMIMEType.Equals("text/html") && !IsSupportedTextType(mContentMIMEType) )
+  {
+      mCloseWindowWhenLoaded = PR_TRUE;
+      mCantEditReason = eCantEditMimeType;
+  }
 
   nsAutoString doneText;
   GetBundleString(NS_LITERAL_STRING("LoadingDone"), doneText);
-  SetChromeAttribute(mDocShell, "statusText", "label", doneText);
+  SetChromeAttribute(mDocShell, "statusText", NS_LITERAL_STRING("label"), doneText);
 
   // Display an Alert dialog if the page cannot be edited...
   if (mCloseWindowWhenLoaded)
@@ -5101,6 +5239,7 @@ nsresult nsEditorShell::EndPageLoad(nsIDOMWindow *aDOMWindow,
   {
     nsCOMPtr<nsIURI>  url;
     aChannel->GetURI(getter_AddRefs(url));
+
     (void) PrepareDocumentForEditing(aDOMWindow, url);
   }
   
@@ -5143,24 +5282,6 @@ nsresult nsEditorShell::EndDocumentLoad(nsIDOMWindow *aDOMWindow,
   nsCOMPtr<nsIRefreshURI> refreshURI = do_QueryInterface(mContentAreaDocShell);
   if (refreshURI)
     refreshURI->CancelRefreshURITimers();
-
-  // Is this a MIME type we can handle?
-  if (aChannel)
-  {
-    char  *contentType;
-    aChannel->GetContentType(&contentType);
-    if (contentType)
-    {
-      if ( (nsCRT::strcmp(contentType, "text/html") != 0) &&
-           (nsCRT::strcmp(contentType, "text/plain") != 0))
-      {
-        mCloseWindowWhenLoaded = PR_TRUE;
-        mCantEditReason = eCantEditMimeType;
-      }
-  
-      nsMemory::Free(contentType);
-    }
-  }
   
   return NS_OK;
 }
diff --git a/editor/base/nsEditorShell.h b/editor/base/nsEditorShell.h
index c336a0a1391a..1d67651ef326 100644
--- a/editor/base/nsEditorShell.h
+++ b/editor/base/nsEditorShell.h
@@ -158,7 +158,7 @@ class nsEditorShell :   public nsIEditorShell,
     nsresult        UpdateWindowTitleAndRecentMenu(PRBool aSaveToPrefs);
 
     // Helper method which is called at the beginning of a new page load
-    nsresult        StartPageLoad();
+    nsresult        StartPageLoad(nsIChannel *aChannel);
 
     // Helper method which is called when an entire page load finishes
     nsresult        EndPageLoad(nsIDOMWindow *aDOMWindow,
@@ -174,6 +174,8 @@ class nsEditorShell :   public nsIEditorShell,
                                     nsIChannel *aChannel,
                                     nsresult aStatus);
 
+    PRBool          IsSupportedTextType(const char* aMIMEType);
+    
     // Check a preference and call NormalizeTable if pref is true
     // Use after deleting or inserting table cells to automatically 
     //  fix rowspan, colspan, and missing cells problems
@@ -234,8 +236,11 @@ class nsEditorShell :   public nsIEditorShell,
     PRPackedBool        mCloseWindowWhenLoaded; // error on load. Close window when loaded
     ECantEditReason     mCantEditReason;
     
-    EEditorType          mEditorType;
+    EEditorType         mEditorType;
     nsString            mEditorTypeString;      // string which describes which editor type will be instantiated (lowercased)
+    nsCString           mContentMIMEType;       // MIME type of the doc we are editing.
+    PRBool              mContentTypeKnown;
+    
     PRInt32             mWrapColumn;            // can't actually set this 'til the editor is created, so we may have to hold on to it for a while
 
     nsStringArray       mSuggestedWordList;
diff --git a/editor/composer/src/nsComposerCommands.cpp b/editor/composer/src/nsComposerCommands.cpp
index 21cbbfb12c2b..1fdcaee387ff 100644
--- a/editor/composer/src/nsComposerCommands.cpp
+++ b/editor/composer/src/nsComposerCommands.cpp
@@ -94,6 +94,24 @@ nsBaseComposerCommand::SetCommandNodeState(const nsAReadableString & aCommandNam
   return uiNode->SetAttribute(NS_ConvertASCIItoUCS2("state"), inNodeState);
 }
 
+//--------------------------------------------------------------------------------------------------------------------
+PRBool
+nsBaseComposerCommand::EditingHTML(nsIEditorShell* inEditorShell)
+//--------------------------------------------------------------------------------------------------------------------
+{
+  nsXPIDLCString  mimeType;
+  inEditorShell->GetContentsMIMEType(getter_Copies(mimeType));
+  if (nsCRT::strcmp(mimeType, "text/html") != 0)
+    return PR_FALSE;
+
+  PRBool sourceMode = PR_FALSE;
+  inEditorShell->IsHTMLSourceMode(&sourceMode);
+  if (sourceMode)
+    return PR_FALSE;
+    
+  return PR_TRUE;
+}
+
 
 #ifdef XP_MAC
 #pragma mark -
@@ -119,23 +137,12 @@ nsBaseStateUpdatingCommand::IsCommandEnabled(const nsAReadableString & aCommandN
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;  
-  if (!editorShell) return NS_OK;
-  // check for plain text?
-  nsCOMPtr<nsIEditor> editor;
-  editorShell->GetEditor(getter_AddRefs(editor));
-  if (!editor) return NS_OK;
  
-  // Enable commands only if not in HTML source edit mode
-  PRBool sourceMode = PR_FALSE;
-  editorShell->IsHTMLSourceMode(&sourceMode);
-  *outCmdEnabled = !sourceMode;
-    
-  // also udpate the command state  
-  nsresult rv = UpdateCommandState(aCommandName, refCon);
-  if (NS_FAILED(rv))
+  if (editorShell && EditingHTML(editorShell))
   {
-    *outCmdEnabled = PR_FALSE;
-    return NS_OK;
+    *outCmdEnabled = PR_TRUE;
+    // also udpate the command state. 
+    UpdateCommandState(aCommandName, refCon);
   }
   
   return NS_OK;
@@ -472,7 +479,7 @@ nsRemoveListCommand::IsCommandEnabled(const nsAReadableString & aCommandName, ns
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     // It is enabled if we are in any list type
     PRBool bMixed;
@@ -515,7 +522,7 @@ nsIndentCommand::IsCommandEnabled(const nsAReadableString & aCommandName, nsISup
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -547,7 +554,7 @@ nsOutdentCommand::IsCommandEnabled(const nsAReadableString & aCommandName, nsISu
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -571,7 +578,7 @@ nsOutdentCommand::DoCommand(const nsAReadableString & aCommandName, nsISupports
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
 
   nsresult rv = NS_OK;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsAutoString indentStr; indentStr.AssignWithConversion("outdent");
     rv = editorShell->Indent(indentStr.GetUnicode());
@@ -602,7 +609,7 @@ nsMultiStateCommand::IsCommandEnabled(const nsAReadableString & aCommandName, ns
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -923,7 +930,7 @@ nsRemoveStylesCommand::IsCommandEnabled(const nsAReadableString & aCommandName,
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -968,7 +975,7 @@ nsIncreaseFontSizeCommand::IsCommandEnabled(const nsAReadableString & aCommandNa
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
@@ -1006,7 +1013,7 @@ nsDecreaseFontSizeCommand::IsCommandEnabled(const nsAReadableString & aCommandNa
 {
   nsCOMPtr<nsIEditorShell> editorShell = do_QueryInterface(refCon);
   *outCmdEnabled = PR_FALSE;
-  if (editorShell)
+  if (editorShell && EditingHTML(editorShell))
   {
     nsCOMPtr<nsIEditor> editor;
     editorShell->GetEditor(getter_AddRefs(editor));
diff --git a/editor/composer/src/nsComposerCommands.h b/editor/composer/src/nsComposerCommands.h
index 50948aa96006..bae9a8c690cf 100644
--- a/editor/composer/src/nsComposerCommands.h
+++ b/editor/composer/src/nsComposerCommands.h
@@ -59,6 +59,8 @@ protected:
   nsresult    GetCommandNodeState(const nsAReadableString & aCommandName, nsIEditorShell* editorShell, nsString& outNodeState);
   nsresult    SetCommandNodeState(const nsAReadableString & aCommandName, nsIEditorShell* editorShell, const nsString& inNodeState);
 
+  // are we in HTML edit mode (not source view or plain text editing)
+  PRBool      EditingHTML(nsIEditorShell* inEditorShell);
 };
 
 
diff --git a/editor/composer/src/nsEditorShell.cpp b/editor/composer/src/nsEditorShell.cpp
index efc4de68c926..7dd268d567c0 100644
--- a/editor/composer/src/nsEditorShell.cpp
+++ b/editor/composer/src/nsEditorShell.cpp
@@ -100,6 +100,8 @@
 #include "nsILookAndFeel.h"
 
 #include "nsIChromeRegistry.h"
+#include "nsCExternalHandlerService.h"
+#include "nsIMIMEService.h"
 
 ///////////////////////////////////////
 // Editor Includes
@@ -207,13 +209,14 @@ GetChromeElement(nsIDocShell *aShell, const char *aID, nsIDOMElement **aElement)
 // Utility to set and attribute of a UI element
 static nsresult 
 SetChromeAttribute(nsIDocShell *aShell, const char *aID, 
-                    const char *aName,  const nsString &aValue)
+                    const nsAString& aName,  const nsAString &aValue)
 {
   nsCOMPtr<nsIDOMElement> elem;
   nsresult rv = GetChromeElement(aShell, aID, getter_AddRefs(elem));
+
+  // Set the text attribute.
   if (NS_SUCCEEDED(rv) && elem)
-    // Set the text attribute.
-    rv = elem->SetAttribute( NS_ConvertASCIItoUCS2(aName), aValue);
+    rv = elem->SetAttribute(aName, aValue);
 
   return rv;
 }
@@ -254,6 +257,8 @@ nsEditorShell::nsEditorShell()
 ,  mCloseWindowWhenLoaded(PR_FALSE)
 ,  mCantEditReason(eCantEditNoReason)
 ,  mEditorType(eUninitializedEditorType)
+,  mContentMIMEType("text/html")
+,  mContentTypeKnown(PR_FALSE)
 ,  mWrapColumn(0)
 ,  mSuggestedWordIndex(0)
 ,  mDictionaryIndex(0)
@@ -436,6 +441,37 @@ nsEditorShell::ResetEditingState()
   return NS_OK;
 }
 
+
+// is this a MIME type that we support the editing of, in plain text mode?
+const char* const gSupportedTextTypes[] = {
+  "text/plain",
+  "text/css",
+  "text/rdf",
+  "text/xml",
+  "text/xsl",
+  "text/javascript",    // obsolete type
+  "application/x-javascript",
+  "text/xul",           // obsolete type
+  "application/vnd.mozilla.xul+xml",
+  NULL      // IMPORTANT! Null must be at end
+};
+
+PRBool
+nsEditorShell::IsSupportedTextType(const char* aMIMEType)
+{
+  PRInt32   i = 0;
+  
+  while (gSupportedTextTypes[i])
+  {
+    if (nsCRT::strcmp(gSupportedTextTypes[i], aMIMEType) == 0)
+      return PR_TRUE;
+  
+    i ++;
+  }
+  
+  return PR_FALSE;
+}
+
 nsresult    
 nsEditorShell::PrepareDocumentForEditing(nsIDOMWindow* aDOMWindow, nsIURI *aUrl)
 {
@@ -884,6 +920,21 @@ nsEditorShell::GetEditorType(PRUnichar **_retval)
   return NS_OK;
 }
 
+/* attribute string contentsMIMEType; */
+NS_IMETHODIMP
+nsEditorShell::GetContentsMIMEType(char * *aContentsMIMEType)
+{
+  NS_ENSURE_ARG_POINTER(aContentsMIMEType);
+  *aContentsMIMEType = mContentMIMEType.ToNewCString();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsEditorShell::SetContentsMIMEType(const char * aContentsMIMEType)
+{
+  mContentMIMEType.Assign(aContentsMIMEType ? aContentsMIMEType : "");
+  return NS_OK;
+}
 
 nsresult
 nsEditorShell::InstantiateEditor(nsIDOMDocument *aDoc, nsIPresShell *aPresShell)
@@ -895,58 +946,66 @@ nsEditorShell::InstantiateEditor(nsIDOMDocument *aDoc, nsIPresShell *aPresShell)
   if (mEditor)
     return NS_ERROR_ALREADY_INITIALIZED;
 
-  nsresult err = NS_OK;
+  nsresult rv = NS_OK;
   
   nsCOMPtr<nsIEditor> editor;
-  err = nsComponentManager::CreateInstance(kHTMLEditorCID, nsnull, NS_GET_IID(nsIEditor), getter_AddRefs(editor));
-  if(!editor)
-    err = NS_ERROR_OUT_OF_MEMORY;
+  rv = nsComponentManager::CreateInstance(kHTMLEditorCID, nsnull, NS_GET_IID(nsIEditor), getter_AddRefs(editor));
+  if (NS_FAILED(rv)) return rv;
+
   nsCOMPtr<nsISelectionController> selCon = do_QueryInterface(aPresShell);
   
-  if (NS_SUCCEEDED(err))
+  if (mEditorTypeString.EqualsWithConversion("text"))
   {
-    if (mEditorTypeString.EqualsWithConversion("text"))
+    PRInt16 flags = nsIPlaintextEditor::eEditorPlaintextMask | nsIPlaintextEditor::eEditorEnableWrapHackMask;
+    if (mMailCompose) flags |= nsIPlaintextEditor::eEditorMailMask;
+    rv = editor->Init(aDoc, aPresShell, nsnull, selCon, flags);
+    mEditorType = ePlainTextEditorType;
+  }
+  else if (mEditorTypeString.EqualsWithConversion("html") || mEditorTypeString.IsEmpty())  // empty string default to HTML editor
+  {
+    PRUint32    editorFlags = 0;
+    EEditorType editorType  = eHTMLTextEditorType;
+    
+    // if the MIME type of the docment we are editing is text/plain, make a text editor
+    if (IsSupportedTextType(mContentMIMEType))
     {
-      PRInt16 flags = nsIPlaintextEditor::eEditorPlaintextMask | nsIPlaintextEditor::eEditorEnableWrapHackMask;
-      if (mMailCompose) flags |= nsIPlaintextEditor::eEditorMailMask;
-      err = editor->Init(aDoc, aPresShell, nsnull, selCon, flags);
-      mEditorType = ePlainTextEditorType;
+      editorFlags = nsIPlaintextEditor::eEditorPlaintextMask;
+      editorType  = ePlainTextEditorType;
     }
-    else if (mEditorTypeString.EqualsWithConversion("html") || mEditorTypeString.IsEmpty())  // empty string default to HTML editor
-    {
-      err = editor->Init(aDoc, aPresShell, nsnull, selCon, 0);
-      mEditorType = eHTMLTextEditorType;
-    }
-    else if (mEditorTypeString.EqualsWithConversion("htmlmail"))  //  HTML editor with special mail rules
-    {
-      err = editor->Init(aDoc, aPresShell, nsnull, selCon, nsIPlaintextEditor::eEditorMailMask);
-      mEditorType = eHTMLTextEditorType;
-    }
-    else
-    {
-      err = NS_ERROR_INVALID_ARG;    // this is not an editor we know about
+    
+    rv = editor->Init(aDoc, aPresShell, nsnull, selCon, editorFlags);
+    mEditorType = editorType;
+  }
+  else if (mEditorTypeString.EqualsWithConversion("htmlmail"))  //  HTML editor with special mail rules
+  {
+    rv = editor->Init(aDoc, aPresShell, nsnull, selCon, nsIPlaintextEditor::eEditorMailMask);
+    mEditorType = eHTMLTextEditorType;
+  }
+  else
+  {
+    rv = NS_ERROR_INVALID_ARG;    // this is not an editor we know about
 #if DEBUG
-      nsAutoString  errorMsg; errorMsg.AssignWithConversion("Failed to init editor. Unknown editor type \"");
-      errorMsg += mEditorTypeString;
-      errorMsg.AppendWithConversion("\"\n");
-      char  *errorMsgCString = errorMsg.ToNewCString();
-         NS_WARNING(errorMsgCString);
-         nsCRT::free(errorMsgCString);
+    nsAutoString  errorMsg; errorMsg.AssignWithConversion("Failed to init editor. Unknown editor type \"");
+    errorMsg += mEditorTypeString;
+    errorMsg.AppendWithConversion("\"\n");
+    char  *errorMsgCString = errorMsg.ToNewCString();
+    NS_WARNING(errorMsgCString);
+    nsCRT::free(errorMsgCString);
 #endif
-    }
+  }
 
     // disable the preference style sheet so we can override colors
-    if (NS_SUCCEEDED(err)) {
-      err = aPresShell->EnablePrefStyleRules(PR_FALSE,0);
-    }
+  if (NS_SUCCEEDED(rv))
+  {
+    rv = aPresShell->EnablePrefStyleRules(PR_FALSE,0);
+  }
 
-    if (NS_SUCCEEDED(err) && editor)
-    {
-      mEditor = do_QueryInterface(editor);    // this does the addref that is the owning reference
-    }
+  if (NS_SUCCEEDED(rv) && editor)
+  {
+    mEditor = do_QueryInterface(editor);    // this does the addref that is the owning reference
   }
     
-  return err;
+  return rv;
 }
 
 
@@ -1688,6 +1747,27 @@ nsEditorShell::CheckOpenWindowForURLMatch(const PRUnichar* inFileURL, nsIDOMWind
   return NS_OK;
 }
 
+// helper function
+static nsresult GetExtensionForMIMEType(const char* inMIMEType, nsACString& outExtension)
+{
+  nsresult  rv;
+  nsCOMPtr<nsIMIMEService> mimeService = do_GetService(NS_MIMESERVICE_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return rv;
+  
+  nsCOMPtr<nsIMIMEInfo>   mimeInfo;
+  rv = mimeService->GetFromMIMEType(inMIMEType, getter_AddRefs(mimeInfo));
+  if (NS_FAILED(rv)) return rv;
+
+  nsXPIDLCString  fileExtension;
+  rv = mimeInfo->FirstExtension(getter_Copies(fileExtension));
+  if (NS_FAILED(rv)) return rv;
+  
+  outExtension.Assign(fileExtension);
+
+  return NS_OK;
+}
+
+
 NS_IMETHODIMP 
 nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* aMimeType, PRBool *_retval)
 {
@@ -1696,13 +1776,20 @@ nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* a
 
   NS_ENSURE_ARG_POINTER((aMimeType));
 
-  nsAutoString mimeType(aMimeType);
-  PRBool saveAsText = mimeType.EqualsWithConversion("text/plain");
+  nsCAutoString mimeTypeCStr; mimeTypeCStr.AssignWithConversion(aMimeType);
+  PRBool saveAsText = IsSupportedTextType(mimeTypeCStr);
 
   // Currently, we only understand plain text and html
-  if (!mimeType.EqualsWithConversion("text/html") && !saveAsText)
+  if (!mimeTypeCStr.Equals("text/html") && !saveAsText)
     return NS_ERROR_FAILURE;
 
+  nsAutoString    mimeType(aMimeType);
+  
+  // if we're saving as text, force the text/plain MIME type (because we use this
+  // to get a content serializer on save)
+  if (saveAsText)
+    mimeType.Assign(NS_LITERAL_STRING("text/plain").get());
+  
   switch (mEditorType)
   {
     case ePlainTextEditorType:
@@ -1858,11 +1945,12 @@ nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* a
                 title.ReplaceChar(" .\\/@:", (PRUnichar)'_');
               }
 
+              // get the correct extension from the MIME type here
               fileName = title;
-              if (saveAsText)
-                fileName.AppendWithConversion(".txt");
-              else
-                fileName.AppendWithConversion(".html");
+              nsCAutoString fileExt(saveAsText ? "txt" : "html");
+              GetExtensionForMIMEType(mimeTypeCStr.get(), fileExt);
+              fileName.Append(PRUnichar('.'));
+              fileName.AppendWithConversion(fileExt);
             } 
             else  // have a file spec
             {
@@ -1881,9 +1969,12 @@ nsEditorShell::SaveDocument(PRBool aSaveAs, PRBool aSaveCopy, const PRUnichar* a
                   index = fileName.RFind(".shtml", PR_TRUE);
                 if (index > 0)
                 {
+                  nsCAutoString fileExt("txt");
+                  GetExtensionForMIMEType(mimeTypeCStr.get(), fileExt);
+
                   // Truncate after "." and append "txt" extension
                   fileName.SetLength(index+1);
-                  fileName.AppendWithConversion("txt");
+                  fileName.AppendWithConversion(fileExt);
                 }
               }
 
@@ -4934,6 +5025,8 @@ nsEditorShell::OnStateChange(nsIWebProgress *aProgress,
                              PRInt32 aStateFlags,
                              nsresult aStatus)
 {
+  nsresult    rv = NS_OK;
+  
   //
   // A Request has started...
   //
@@ -4942,7 +5035,8 @@ nsEditorShell::OnStateChange(nsIWebProgress *aProgress,
     // Page level notification...
     if (aStateFlags & nsIWebProgressListener::STATE_IS_NETWORK)
     {
-      StartPageLoad();
+      nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+      StartPageLoad(channel);
     }
     // Document level notification...
     if (aStateFlags & nsIWebProgressListener::STATE_IS_DOCUMENT)
@@ -5013,12 +5107,36 @@ nsEditorShell::OnSecurityChange(nsIWebProgress *aWebProgress,
   return NS_OK;
 }
 
-nsresult nsEditorShell::StartPageLoad()
+nsresult nsEditorShell::StartPageLoad(nsIChannel *aChannel)
 {
+  nsXPIDLCString  contentType;
+  aChannel->GetContentType(getter_Copies(contentType));
+  
+  // save the original MIME type; we'll use it later
+  mContentMIMEType.Assign(contentType.get() ? contentType : "");
+  
+  if (nsCRT::strcmp(contentType, "text/html") == 0)
+  {
+    // fine, do nothing
+    mContentTypeKnown = PR_TRUE;
+  }
+  else if (IsSupportedTextType(contentType))
+  {
+    // set the mime type to text/plain so that it renders as text
+    aChannel->SetContentType("text/plain");
+    mContentTypeKnown = PR_TRUE;
+  }
+  else
+  {
+    // we don't know what this is yet. It might be HTML loaded from 
+    // a directory URL (http://www.foo.com/). We'll know the real
+    // MIME type later.
+    mContentTypeKnown = PR_FALSE;
+  }
+
   // Start the throbber
   // TODO: We should also start/stop it for saving and publishing?
-  SetChromeAttribute( mDocShell, "Editor:Throbber", "busy", 
-                      NS_ConvertASCIItoUCS2("true") );
+  SetChromeAttribute( mDocShell, "Editor:Throbber", NS_LITERAL_STRING("busy"), NS_LITERAL_STRING("true") );
 
   // set up a parser observer
   if (!mParserObserver)
@@ -5029,6 +5147,7 @@ nsresult nsEditorShell::StartPageLoad()
     }
     NS_ADDREF(mParserObserver);
     mParserObserver->RegisterTagToWatch("FRAMESET");
+    mParserObserver->RegisterTagToWatch("IFRAME");
     mParserObserver->Start();
   }
 
@@ -5048,12 +5167,31 @@ nsresult nsEditorShell::EndPageLoad(nsIDOMWindow *aDOMWindow,
     NS_RELEASE(mParserObserver);
   }
 
-  SetChromeAttribute( mDocShell, "Editor:Throbber", "busy", 
-                      NS_ConvertASCIItoUCS2("false") );
+  SetChromeAttribute( mDocShell, "Editor:Throbber", NS_LITERAL_STRING("busy"), NS_LITERAL_STRING("false") );
+
+  // Is this a MIME type we can handle?
+  if (aChannel)
+  {
+    // if we didn't get the content-type at the start of the load, get it now
+    if (!mContentTypeKnown)
+    {
+      nsXPIDLCString  contentType;
+      aChannel->GetContentType(getter_Copies(contentType));
+
+      if (contentType.get())
+        mContentMIMEType.Assign(contentType);
+    }
+  }    
+    
+  if ( !mContentMIMEType.Equals("text/html") && !IsSupportedTextType(mContentMIMEType) )
+  {
+      mCloseWindowWhenLoaded = PR_TRUE;
+      mCantEditReason = eCantEditMimeType;
+  }
 
   nsAutoString doneText;
   GetBundleString(NS_LITERAL_STRING("LoadingDone"), doneText);
-  SetChromeAttribute(mDocShell, "statusText", "label", doneText);
+  SetChromeAttribute(mDocShell, "statusText", NS_LITERAL_STRING("label"), doneText);
 
   // Display an Alert dialog if the page cannot be edited...
   if (mCloseWindowWhenLoaded)
@@ -5101,6 +5239,7 @@ nsresult nsEditorShell::EndPageLoad(nsIDOMWindow *aDOMWindow,
   {
     nsCOMPtr<nsIURI>  url;
     aChannel->GetURI(getter_AddRefs(url));
+
     (void) PrepareDocumentForEditing(aDOMWindow, url);
   }
   
@@ -5143,24 +5282,6 @@ nsresult nsEditorShell::EndDocumentLoad(nsIDOMWindow *aDOMWindow,
   nsCOMPtr<nsIRefreshURI> refreshURI = do_QueryInterface(mContentAreaDocShell);
   if (refreshURI)
     refreshURI->CancelRefreshURITimers();
-
-  // Is this a MIME type we can handle?
-  if (aChannel)
-  {
-    char  *contentType;
-    aChannel->GetContentType(&contentType);
-    if (contentType)
-    {
-      if ( (nsCRT::strcmp(contentType, "text/html") != 0) &&
-           (nsCRT::strcmp(contentType, "text/plain") != 0))
-      {
-        mCloseWindowWhenLoaded = PR_TRUE;
-        mCantEditReason = eCantEditMimeType;
-      }
-  
-      nsMemory::Free(contentType);
-    }
-  }
   
   return NS_OK;
 }
diff --git a/editor/composer/src/nsEditorShell.h b/editor/composer/src/nsEditorShell.h
index c336a0a1391a..1d67651ef326 100644
--- a/editor/composer/src/nsEditorShell.h
+++ b/editor/composer/src/nsEditorShell.h
@@ -158,7 +158,7 @@ class nsEditorShell :   public nsIEditorShell,
     nsresult        UpdateWindowTitleAndRecentMenu(PRBool aSaveToPrefs);
 
     // Helper method which is called at the beginning of a new page load
-    nsresult        StartPageLoad();
+    nsresult        StartPageLoad(nsIChannel *aChannel);
 
     // Helper method which is called when an entire page load finishes
     nsresult        EndPageLoad(nsIDOMWindow *aDOMWindow,
@@ -174,6 +174,8 @@ class nsEditorShell :   public nsIEditorShell,
                                     nsIChannel *aChannel,
                                     nsresult aStatus);
 
+    PRBool          IsSupportedTextType(const char* aMIMEType);
+    
     // Check a preference and call NormalizeTable if pref is true
     // Use after deleting or inserting table cells to automatically 
     //  fix rowspan, colspan, and missing cells problems
@@ -234,8 +236,11 @@ class nsEditorShell :   public nsIEditorShell,
     PRPackedBool        mCloseWindowWhenLoaded; // error on load. Close window when loaded
     ECantEditReason     mCantEditReason;
     
-    EEditorType          mEditorType;
+    EEditorType         mEditorType;
     nsString            mEditorTypeString;      // string which describes which editor type will be instantiated (lowercased)
+    nsCString           mContentMIMEType;       // MIME type of the doc we are editing.
+    PRBool              mContentTypeKnown;
+    
     PRInt32             mWrapColumn;            // can't actually set this 'til the editor is created, so we may have to hold on to it for a while
 
     nsStringArray       mSuggestedWordList;
diff --git a/editor/idl/nsIEditorShell.idl b/editor/idl/nsIEditorShell.idl
index 4e3337c039e4..369af00827de 100644
--- a/editor/idl/nsIEditorShell.idl
+++ b/editor/idl/nsIEditorShell.idl
@@ -45,6 +45,7 @@ interface nsIEditorShell : nsISupports
   attribute nsIDOMWindowInternal webShellWindow;
   attribute nsIDOMWindowInternal contentWindow;
   attribute wstring              editorType;
+  attribute string               contentsMIMEType;
            
   readonly attribute nsIEditor editor;
   
diff --git a/editor/ui/composer/content/ComposerCommands.js b/editor/ui/composer/content/ComposerCommands.js
index 46fc0d1f0651..7610d5ac9ac8 100644
--- a/editor/ui/composer/content/ComposerCommands.js
+++ b/editor/ui/composer/content/ComposerCommands.js
@@ -25,9 +25,6 @@
 /* Implementations of nsIControllerCommand for composer commands */
 
 
-var promptService = Components.classes["@mozilla.org/embedcomp/prompt-service;1"].getService();
-promptService = promptService.QueryInterface(Components.interfaces.nsIPromptService);
-
 //-----------------------------------------------------------------------------------
 function SetupHTMLEditorCommands()
 {
@@ -39,7 +36,9 @@ function SetupHTMLEditorCommands()
   // Include everthing a text editor does
   SetupTextEditorCommands();
 
-  dump("Registering HTML editor commands\n");
+  //dump("Registering HTML editor commands\n");
+
+  controller.registerCommand("cmd_renderedHTMLEnabler",           nsDummyHTMLCommand);
 
   controller.registerCommand("cmd_listProperties",  nsListPropertiesCommand);
   controller.registerCommand("cmd_pageProperties",  nsPagePropertiesCommand);
@@ -92,7 +91,7 @@ function SetupTextEditorCommands()
   if (!controller)
     return;
   
-  dump("Registering plain text editor commands\n");
+  //dump("Registering plain text editor commands\n");
   
   controller.registerCommand("cmd_find",       nsFindCommand);
   controller.registerCommand("cmd_findNext",   nsFindNextCommand);
@@ -179,7 +178,7 @@ function SetupComposerWindowCommands()
 function GetEditorController()
 {
   var numControllers = window._content.controllers.getControllerCount();
-  
+    
   // count down to find a controller that supplies a nsIControllerCommandManager interface
   for (var i = numControllers; i >= 0 ; i --)
   {
@@ -187,11 +186,16 @@ function GetEditorController()
     
     try { 
       var controller = window._content.controllers.getControllerAt(i);
+      
       var interfaceRequestor = controller.QueryInterface(Components.interfaces.nsIInterfaceRequestor);
       if (!interfaceRequestor) continue;
     
       commandManager = interfaceRequestor.getInterface(Components.interfaces.nsIControllerCommandManager);
-    } catch(ex) {}
+    }
+    catch(ex)
+    {
+        //dump(ex + "\n");
+    }
 
     if (commandManager)
       return commandManager;
@@ -240,6 +244,22 @@ function PrintNodeID(id)
   PrintObject(document.getElementById(id));
 }
 
+//-----------------------------------------------------------------------------------
+var nsDummyHTMLCommand =
+{
+  isCommandEnabled: function(aCommand, dummy)
+  {
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
+  },
+
+  doCommand: function(aCommand)
+  {
+    // do nothing
+    dump("Hey, who's calling the dummy command?\n");
+  }
+
+};
+
 //-----------------------------------------------------------------------------------
 var nsOpenCommand =
 {
@@ -295,7 +315,7 @@ var nsSaveCommand =
     {
       FinishHTMLSource(); // In editor.js
       var doSaveAs = window.editorShell.editorDocument.location == "about:blank";
-      var result = window.editorShell.saveDocument(doSaveAs, false, window.gDefaultSaveMimeType);
+      var result = window.editorShell.saveDocument(doSaveAs, false, editorShell.contentsMIMEType);
       window._content.focus();
       return result;
     }
@@ -315,7 +335,7 @@ var nsSaveAsCommand =
     if (window.editorShell)
     {
       FinishHTMLSource();
-      var result = window.editorShell.saveDocument(true, false, window.gDefaultSaveMimeType);
+      var result = window.editorShell.saveDocument(true, false, editorShell.contentsMIMEType);
       window._content.focus();
       return result;
     }
@@ -363,7 +383,7 @@ var nsSaveAsCharsetCommand =
       }
       else
       {
-      window.ok = window.editorShell.saveDocument(true, false, window.gDefaultSaveMimeType);
+        window.ok = window.editorShell.saveDocument(true, false, editorShell.contentsMIMEType);
       }
     }
     window._content.focus();
@@ -384,6 +404,9 @@ var nsRevertCommand =
   doCommand: function(aCommand)
   {
     // Confirm with the user to abandon current changes
+    var promptService = Components.classes["@mozilla.org/embedcomp/prompt-service;1"].getService();
+    promptService = promptService.QueryInterface(Components.interfaces.nsIPromptService);
+
     if (promptService)
     {
       var result = {value:0};
@@ -477,7 +500,7 @@ var nsPreviewCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell != null && (DocumentHasBeenSaved() || window.editorShell.documentModified));
+    return (window.editorShell && IsEditorContentHTML() && (DocumentHasBeenSaved() || window.editorShell.documentModified));
   },
 
   doCommand: function(aCommand)
@@ -612,7 +635,7 @@ var nsImageCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -626,7 +649,7 @@ var nsHLineCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -695,7 +718,7 @@ var nsLinkCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -709,7 +732,7 @@ var nsAnchorCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -723,7 +746,7 @@ var nsInsertHTMLCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -737,7 +760,7 @@ var nsInsertCharsCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -750,7 +773,7 @@ var nsInsertBreakCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -763,7 +786,7 @@ var nsInsertBreakAllCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -776,7 +799,7 @@ var nsListPropertiesCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -791,7 +814,7 @@ var nsPagePropertiesCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -806,7 +829,7 @@ var nsObjectPropertiesCommand =
   isCommandEnabled: function(aCommand, dummy)
   {
     var isEnabled = false;
-    if (window.editorShell && window.editorShell.documentEditable)
+    if (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML())
     {
       isEnabled = (GetObjectForProperties() != null ||
                    window.editorShell.GetSelectedElement("href") != null);
@@ -870,7 +893,7 @@ var nsSetSmiley =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return ( window.editorShell && window.editorShell.documentEditable);
+    return ( window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
 
   },
 
@@ -959,7 +982,7 @@ var nsAdvancedPropertiesCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -974,7 +997,7 @@ var nsColorPropertiesCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -989,7 +1012,7 @@ var nsRemoveLinksCommand =
   isCommandEnabled: function(aCommand, dummy)
   {
     // We could see if there's any link in selection, but it doesn't seem worth the work!
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -1004,7 +1027,7 @@ var nsNormalModeCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return true; //(window.editorShell && window.editorShell.documentEditable);
+    return IsEditorContentHTML(); //(window.editorShell && window.editorShell.documentEditable);
   },
   doCommand: function(aCommand)
   {
@@ -1017,7 +1040,7 @@ var nsAllTagsModeCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditorContentHTML());
   },
   doCommand: function(aCommand)
   {
@@ -1030,7 +1053,7 @@ var nsHTMLSourceModeCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditorContentHTML());
   },
   doCommand: function(aCommand)
   {
@@ -1043,7 +1066,7 @@ var nsPreviewModeCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditorContentHTML());
   },
   doCommand: function(aCommand)
   {
@@ -1058,7 +1081,7 @@ var nsInsertOrEditTableCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML());
   },
   doCommand: function(aCommand)
   {
@@ -1153,7 +1176,7 @@ var nsInsertTableCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    return (window.editorShell && window.editorShell.documentEditable);
+    return window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML();
   },
   doCommand: function(aCommand)
   {
@@ -1359,7 +1382,7 @@ var nsJoinTableCellsCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    if (window.editorShell && window.editorShell.documentEditable)
+    if (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML())
     {
       var tagNameObj = new Object;
       var countObj = new Object;
@@ -1407,7 +1430,7 @@ var nsSplitTableCellCommand =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
-    if (window.editorShell && window.editorShell.documentEditable)
+    if (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML())
     {
       var tagNameObj = new Object;
       var countObj = new Object;
@@ -1507,6 +1530,8 @@ var nsConvertToTable =
 {
   isCommandEnabled: function(aCommand, dummy)
   {
+    if (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML())
+    {
     var selection = window.editorShell.editorSelection;
 
     if (selection && !selection.isCollapsed)
@@ -1525,6 +1550,7 @@ var nsConvertToTable =
         return false
       
       return true;
+      }
     }
     return false;
   },
@@ -1537,3 +1563,4 @@ var nsConvertToTable =
     window._content.focus();
   }
 };
+
diff --git a/editor/ui/composer/content/editor.js b/editor/ui/composer/content/editor.js
index a82e7d85f276..231242879f65 100644
--- a/editor/ui/composer/content/editor.js
+++ b/editor/ui/composer/content/editor.js
@@ -70,7 +70,6 @@ var gColorObj = new Object();
 var gPrefs;
 var gDefaultTextColor = "";
 var gDefaultBackgroundColor = "";
-var gDefaultSaveMimeType = "text/html";
 
 // These must be kept in synch with the XUL <options> lists
 var gFontSizeNames = new Array("xx-small","x-small","small","medium","large","x-large","xx-large");
@@ -110,6 +109,17 @@ function PageIsEmptyAndUntouched()
   return (editorShell != null) && (editorShell.documentIsEmpty == true) && (docWasModified == false);
 }
 
+function IsEditorContentHTML()
+{
+  return (editorShell.contentsMIMEType == "text/html");
+}
+
+// are we editing HTML (i.e. neither in HTML source mode, nor editing a text file)
+function IsEditingRenderedHTML()
+{
+    return IsEditorContentHTML() && (gEditorDisplayMode != DisplayModeSource);
+}
+
 // This is called when the real editor document is created,
 // before it's loaded.
 var DocumentStateListener =
@@ -189,7 +199,7 @@ function EditorStartup(editorType, editorElement)
   EditorSharedStartup();
 
   // Commands specific to the Composer Application window,
-  //  (i.e., not embeded editors)
+  //  (i.e., not embedded editors)
   //  such as file-related commands, HTML Source editing, Edit Modes...
   SetupComposerWindowCommands();
 
@@ -211,17 +221,17 @@ function EditorSharedStartup()
       case "html":
       case "htmlmail":
         SetupHTMLEditorCommands();
-        window.gDefaultSaveMimeType = "text/html";
+        editorShell.contentsMIMEType = "text/html";
         break;
       case "text":
       case "textmail":
         SetupTextEditorCommands();
-        window.gDefaultSaveMimeType = "text/plain";
+        editorShell.contentsMIMEType = "text/plain";
         break;
       default:
         dump("INVALID EDITOR TYPE: "+editorShell.editorType+"\n");
         SetupTextEditorCommands();
-        window.gDefaultSaveMimeType = "text/plain";
+        editorShell.contentsMIMEType = "text/plain";
         break;
   }
 
@@ -395,6 +405,9 @@ function CheckAndSaveDocument(reasonToSave, allowDontSave)
   var dialogMsg = window.editorShell.GetString("SaveFilePrompt");
   dialogMsg = (dialogMsg.replace(/%title%/,title)).replace(/%reason%/,reasonToSave);
 
+  var promptService = Components.classes["@mozilla.org/embedcomp/prompt-service;1"].getService();
+  promptService = promptService.QueryInterface(Components.interfaces.nsIPromptService);
+
   var result = {value:0};
   promptService.confirmEx(window, dialogTitle, dialogMsg,
   						  (promptService.BUTTON_TITLE_SAVE * promptService.BUTTON_POS_0) +
@@ -406,7 +419,7 @@ function CheckAndSaveDocument(reasonToSave, allowDontSave)
    if (result.value == 0)
    {
      // Save
-     var success = window.editorShell.saveDocument(false, false, window.gDefaultSaveMimeType);
+     var success = window.editorShell.saveDocument(false, false, editorShell.contentsMIMEType);
      return success;
    }
 
@@ -1230,15 +1243,15 @@ function SetDisplayMode(mode)
       // Switch to the sourceWindow (second in the deck)
       gContentWindowDeck.setAttribute("index","1");
 
-      DisableMenusForHTMLSource(true);
-
-      //Hide the formating toolbar if not already hidden
+      //Hide the formatting toolbar if not already hidden
       gFormatToolbarHidden = gFormatToolbar.getAttribute("hidden");
       if (gFormatToolbarHidden != "true")
       {
         gFormatToolbar.setAttribute("hidden", "true");
       }
 
+      // update commands to disable stuff
+      window.updateCommands("mode_switch");
       gSourceContentWindow.focus();
     }
     else
@@ -1247,13 +1260,14 @@ function SetDisplayMode(mode)
       gContentWindowDeck.setAttribute("index","0");
 
       // Restore menus and toolbars
-      DisableMenusForHTMLSource(false);
-
       if (gFormatToolbarHidden != "true")
       {
         gFormatToolbar.setAttribute("hidden", gFormatToolbarHidden);
       }
 
+      // update commands to re-enable stuff
+      window.updateCommands("mode_switch");
+
       gContentWindow.focus();
     }
 
@@ -1287,51 +1301,6 @@ function SetDisplayMode(mode)
   return false;
 }
 
-// We disable all items in View menu except Edit mode and sidebar items
-function DisableMenusForHTMLSource(disable)
-{
-  // Disable toolbar buttons
-  DisableItem("spellingButton", disable);
-  DisableItem("imageButton", disable);
-  DisableItem("hlineButton", disable);
-  DisableItem("tableButton", disable);
-  DisableItem("linkButton", disable);
-  DisableItem("namedAnchorButton", disable);
-
-  // Any toolbar can be toggled on/off except the format toolbar
-  DisableItem("viewFormatToolbar", disable);
-
-
-  // Top-level menus that we completely hide
-  CollapseItem("insertMenu", disable);
-  CollapseItem("formatMenu", disable);
-  CollapseItem("tableMenu", disable);
-
-  // Edit menu items
-  DisableItem("menu_find", disable);
-  DisableItem("menu_findnext", disable);
-  DisableItem("menu_replace", disable);
-  DisableItem("menu_checkspelling", disable);
-
-  // Disable all items in the view menu except mode switch items
-  var viewMenu = document.getElementById("viewMenu");
-  // menuitems are children of the menupopup child
-  var children = viewMenu.firstChild.childNodes;
-  for (var i = 0; i < children.length; i++)
-  {
-    var item = children.item(i);
-    if (item.id != "viewToolbar" &&
-        item.id != "viewNormalMode" &&
-        item.id != "viewAllTagsMode" &&
-        item.id != "viewSourceMode" &&
-        item.id != "viewPreviewMode" &&
-        item.id != "sidebar-menu")
-    {
-      DisableItem(item.id, disable);
-    }
-  }
-}
-
 function EditorToggleParagraphMarks()
 {
   var menuItem = document.getElementById("viewParagraphMarks");
@@ -1529,8 +1498,10 @@ function  getUnicharPref(aPrefName, aDefVal)
 
 function EditorInitFormatMenu()
 {
-  InitObjectPropertiesMenuitem("objectProperties");
-  InitRemoveStylesMenuitems("removeStylesMenuitem", "removeLinksMenuitem");
+  try {
+    InitObjectPropertiesMenuitem("objectProperties");
+    InitRemoveStylesMenuitems("removeStylesMenuitem", "removeLinksMenuitem");
+  } catch(ex) {}
   // Set alignment check
 }
 
@@ -1542,10 +1513,13 @@ function InitObjectPropertiesMenuitem(id)
   var menuItem = document.getElementById(id);
   if (!menuItem) return null;
 
-  var element = GetObjectForProperties();
+  var element;
   var menuStr = GetString("ObjectProperties");
   var name;
 
+  if (IsEditingRenderedHTML())
+    element = GetObjectForProperties();
+
   if (element && element.nodeName)
   {
     var objStr = "";
@@ -1671,6 +1645,18 @@ function InitAlignMenu()
 function EditorInitToolbars()
 {
   // Nothing to do now, but we might want some state updating here
+  if (!IsEditorContentHTML())
+  {
+    //Hide the formating toolbar
+    gFormatToolbar.setAttribute("hidden", "true");
+
+    //Hide the edit mode toolbar
+    gEditModeBar.setAttribute("hidden", "true");
+    
+    DisableItem("cmd_viewFormatToolbar", true);
+    DisableItem("cmd_viewEditModeToolbar", true);
+  }
+
 }
 
 function EditorSetDefaultPrefsAndDoctype()
@@ -2044,7 +2030,7 @@ function IsSpellCheckerInstalled()
   var spellcheckerClass = Components.classes["@mozilla.org/spellchecker;1"];
   gHaveSpellChecker = (spellcheckerClass != null);
   gSoughtSpellChecker = true;
-  dump("Have SpellChecker = "+gHaveSpellChecker+"\n");
+  //dump("Have SpellChecker = "+gHaveSpellChecker+"\n");
   return gHaveSpellChecker;
 }
 
@@ -2059,7 +2045,7 @@ function IsFindInstalled()
   var findClass = Components.classes["@mozilla.org/appshell/component/find;1"];
   gHaveFind = (findClass != null);
   gSoughtFind = true;
-  dump("Have Find = "+gHaveFind+"\n");
+  //dump("Have Find = "+gHaveFind+"\n");
   return gHaveFind;
 }
 
@@ -2139,7 +2125,9 @@ function GetPrefsService()
 //   with this "oncreate" hander:
 function EditorInitTableMenu()
 {
-  InitJoinCellMenuitem("menu_JoinTableCells");
+  try {
+    InitJoinCellMenuitem("menu_JoinTableCells");
+  } catch (ex) {}
 
   // Set enable states for all table commands
   goUpdateTableMenuItems(document.getElementById("composerTableMenuItems"));
@@ -2159,7 +2147,12 @@ function InitJoinCellMenuitem(id)
   // Use "Join selected cells if there's more than 1 cell selected
   var tagNameObj = new Object;
   var countObj = new Object;
-  if (window.editorShell.GetSelectedOrParentTableElement(tagNameObj, countObj) && countObj.value > 1)
+  var foundElement;
+  
+  if (IsEditingRenderedHTML())
+    foundElement = window.editorShell.GetSelectedOrParentTableElement(tagNameObj, countObj);
+    
+  if (foundElement && countObj.value > 1)
     menuText = GetString("JoinSelectedCells");
   else
     menuText = GetString("JoinCellToRight");
@@ -2195,9 +2188,9 @@ function InitRemoveStylesMenuitems(removeStylesId, removeLinksId)
 function goUpdateTableMenuItems(commandset)
 {
   var enabled = false;
-
   var enabledIfTable = false;
-  if (window.editorShell && window.editorShell.documentEditable)
+
+  if (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML())
   {
     var selectedCountObj = new Object();
     var tagNameObj = new Object();
@@ -2246,13 +2239,13 @@ function goUpdateTableMenuItems(commandset)
 
 function IsInTable()
 {
-  return (window.editorShell && window.editorShell.documentEditable &&
+  return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML() &&
           null != window.editorShell.GetElementOrParentByTagName("table", null));
 }
 
 function IsInTableCell()
 {
-  return (window.editorShell && window.editorShell.documentEditable &&
+  return (window.editorShell && window.editorShell.documentEditable && IsEditingRenderedHTML() &&
           null != window.editorShell.GetElementOrParentByTagName("td", null));
 }
 
@@ -2476,3 +2469,4 @@ function SwitchInsertCharToAnotherEditorOrClose()
     window.InsertCharWindow.close();
   }
 }
+
diff --git a/editor/ui/composer/content/editor.xul b/editor/ui/composer/content/editor.xul
index da41901d2e80..76a46f43ea59 100644
--- a/editor/ui/composer/content/editor.xul
+++ b/editor/ui/composer/content/editor.xul
@@ -250,7 +250,7 @@
       </box>
     </deck>
 
-    <box id="EditModeToolbar" hidden="false" autostretch="never" valign="middle" persist="hidden collapsed">
+    <box id="EditModeToolbar" hidden="false" autostretch="never" valign="middle" persist="collapsed">
       <tabs id="EditModeTabs" class="tabs-bottom" flex="1">
         <tab id="NormalModeButton"/>
         <tab id="TagModeButton"/>
diff --git a/editor/ui/composer/content/editorOverlay.xul b/editor/ui/composer/content/editorOverlay.xul
index 8b8442d9eaf6..7c12bc90417b 100644
--- a/editor/ui/composer/content/editorOverlay.xul
+++ b/editor/ui/composer/content/editorOverlay.xul
@@ -93,7 +93,7 @@
 
   <commandset id="composerMenuItems"
           commandupdater="true"
-          events="create"
+          events="create, mode_switch"
           oncommandupdate="goUpdateComposerMenuItems(this)"
   >
     <!-- format menu -->
@@ -116,6 +116,9 @@
     <command id="cmd_AllTagsMode"      oncommand="goDoCommand('cmd_AllTagsMode')"    label="&AllTagsMode.label;"/>
     <command id="cmd_HTMLSourceMode"   oncommand="goDoCommand('cmd_HTMLSourceMode')"/>
     <command id="cmd_PreviewMode"      oncommand="goDoCommand('cmd_PreviewMode')"    label="&PreviewMode.label;"/>
+
+    <!-- dummy command used just to disable things in non-HTML modes -->
+    <command id="cmd_renderedHTMLEnabler"/>
   </commandset>
   
   <commandset id="composerSaveMenuItems"
@@ -129,7 +132,8 @@
     <command id="cmd_saveAsCharset"  label="&saveAsCharsetCmd.label;"  oncommand="goDoCommand('cmd_saveAsCharset')"/>
     <command id="cmd_revert"         label="&fileRevert.label;"        oncommand="goDoCommand('cmd_revert')"/>
     <command id="cmd_preview"                                          oncommand="goDoCommand('cmd_preview')"/>
-    <command id="cmd_editSendPage"  label="&sendPageCmd.label;"   accesskey="&sendPage.accesskey;"   oncommand="goDoCommand('cmd_editSendPage')"/>
+    <command id="cmd_editSendPage"   label="&sendPageCmd.label;"
+                                     accesskey="&sendPage.accesskey;"  oncommand="goDoCommand('cmd_editSendPage')"/>
   </commandset>
 
 
@@ -160,7 +164,7 @@
   <!-- style related commands that update on creation, and on selection change -->
   <commandset id="composerStyleMenuItems"
           commandupdater="true"
-          events="create, style"
+          events="create, style, mode_switch"
           oncommandupdate="goUpdateComposerMenuItems(this)"
   >
     <command id="cmd_bold"          state="false"     oncommand="goDoCommand('cmd_bold')"/>
@@ -209,14 +213,21 @@
   </commandset>
 
   <!-- commands updated only when the menu gets created -->
-  <commandset id="composerListMenuItems"  oncommandupdate="goUpdateComposerMenuItems(this)">
+  <commandset id="composerListMenuItems"
+          commandupdater="true"
+          events="create, mode_switch"
+          oncommandupdate="goUpdateComposerMenuItems(this)">
     <!-- List menu  -->
     <command id="cmd_dt"                  oncommand="goDoCommand('cmd_dt')"/>
     <command id="cmd_dd"                  oncommand="goDoCommand('cmd_dd')"/>
     <command id="cmd_removeList"          oncommand="goDoCommand('cmd_removeList')"/>
     <!-- cmd_ul and cmd_ol are shared with toolbar and are in composerStyleMenuItems commandset -->
   </commandset>
-  <commandset id="composerTableMenuItems" oncommandupdate="goUpdateTableMenuItems(this)">
+
+  <commandset id="composerTableMenuItems"
+          commandupdater="true"
+          events="create, mode_switch"
+          oncommandupdate="goUpdateTableMenuItems(this)">
     <!-- Table menu -->
     <command id="cmd_SelectTable"         oncommand="goDoCommand('cmd_SelectTable')"/>
     <command id="cmd_SelectRow"           oncommand="goDoCommand('cmd_SelectRow')"/>
@@ -254,7 +265,7 @@
     <command id="cmd_viewCompToolbar"     oncommand="goToggleToolbar('EditToolbar','cmd_viewCompToolbar');"         checked="true"/>
     <command id="cmd_viewFormatToolbar"   oncommand="goToggleToolbar('FormatToolbar','cmd_viewFormatToolbar');"     checked="true"/>
     <command id="cmd_viewEditModeToolbar" oncommand="goToggleToolbar('EditModeToolbar','cmd_viewEditModeToolbar');" checked="true"/>
-    <command id="cmd_viewtaskbar"         oncommand="goToggleToolbar('status-bar','cmd_viewtaskbar');"                 checked="true"/>
+    <command id="cmd_viewtaskbar"         oncommand="goToggleToolbar('status-bar','cmd_viewtaskbar');"              checked="true"/>
 
     <!-- Obsolete; these will go away -->
     <command id="Editor:Font:Size" fontsize=""/>
@@ -380,12 +391,12 @@
     <menu id="fontFaceMenu" label="&fontfaceMenu.label;" accesskey="&formatfontmenu.accesskey;" 
           position="1">
       <menupopup oncommand="doStatefulCommand('cmd_fontFace', event.target.value)" oncreate="initFontFaceMenu(this)">
-        <menuitem label="&fontVarWidth.label;"      accesskey="&fontvarwidth.accesskey;"    value="" type="radio" name="1"/>
-        <menuitem label="&fontFixedWidth.label;"    accesskey="&fontfixedwidth.accesskey;"  value="tt" type="radio" name="1" key="fontfixedwidthkb"/>
+        <menuitem label="&fontVarWidth.label;"      accesskey="&fontvarwidth.accesskey;"    value=""    type="radio" name="1" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&fontFixedWidth.label;"    accesskey="&fontfixedwidth.accesskey;"  value="tt"  type="radio" name="1" key="fontfixedwidthkb" observes="cmd_renderedHTMLEnabler"/>
         <menuseparator/>
-        <menuitem label="&fontHelveticaFont.label;" accesskey="&fonthelvetica.accesskey;"   value="Helvetica, Arial, sans-serif" type="radio" name="2" />
-        <menuitem label="&fontTimes.label;"         accesskey="&fonttimes.accesskey;"       value="Times New Roman, Times, serif" type="radio" name="2" />
-        <menuitem label="&fontCourier.label;"       accesskey="&fontcourier.accesskey;"     value="Courier New, Courier, monospace" type="radio" name="2" />
+        <menuitem label="&fontHelveticaFont.label;" accesskey="&fonthelvetica.accesskey;"   value="Helvetica, Arial, sans-serif"    type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&fontTimes.label;"         accesskey="&fonttimes.accesskey;"       value="Times New Roman, Times, serif"   type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&fontCourier.label;"       accesskey="&fontcourier.accesskey;"     value="Courier New, Courier, monospace" type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
       </menupopup>
     </menu>
 
@@ -400,12 +411,12 @@
 <!-- Not supported in current font size implementation
         <menuitem label="&size-xx-smallCmd.label;" accesskey="&size-xx-small.accesskey;" oncommand="EditorSetFontSize('xx-small')" type="radio" name="2" />
 -->
-        <menuitem label="&size-x-smallCmd.label;"  accesskey="&size-x-small.accesskey;"  oncommand="EditorSetFontSize('x-small')" type="radio" name="2" />
-        <menuitem label="&size-smallCmd.label;"    accesskey="&size-small.accesskey;"    oncommand="EditorSetFontSize('small')" type="radio" name="2" />
-        <menuitem label="&size-mediumCmd.label;"   accesskey="&size-medium.accesskey;"   oncommand="EditorSetFontSize('medium')" type="radio" name="2" />
-        <menuitem label="&size-largeCmd.label;"    accesskey="&size-large.accesskey;"    oncommand="EditorSetFontSize('large')" type="radio" name="2" />
-        <menuitem label="&size-x-largeCmd.label;"  accesskey="&size-x-large.accesskey;"  oncommand="EditorSetFontSize('x-large')" type="radio" name="2" />
-        <menuitem label="&size-xx-largeCmd.label;" accesskey="&size-xx-large.accesskey;" oncommand="EditorSetFontSize('xx-large')" type="radio" name="2" />
+        <menuitem label="&size-x-smallCmd.label;"  accesskey="&size-x-small.accesskey;"  oncommand="EditorSetFontSize('x-small')"  type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&size-smallCmd.label;"    accesskey="&size-small.accesskey;"    oncommand="EditorSetFontSize('small')"    type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&size-mediumCmd.label;"   accesskey="&size-medium.accesskey;"   oncommand="EditorSetFontSize('medium')"   type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&size-largeCmd.label;"    accesskey="&size-large.accesskey;"    oncommand="EditorSetFontSize('large')"    type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&size-x-largeCmd.label;"  accesskey="&size-x-large.accesskey;"  oncommand="EditorSetFontSize('x-large')"  type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
+        <menuitem label="&size-xx-largeCmd.label;" accesskey="&size-xx-large.accesskey;" oncommand="EditorSetFontSize('xx-large')" type="radio" name="2" observes="cmd_renderedHTMLEnabler"/>
       </menupopup>
     </menu>
 
@@ -435,7 +446,8 @@
     
     <menuitem id="fontColor" label="&formatFontColor.label;" 
           accesskey="&formatfontcolor.accesskey;"
-          oncommand="EditorSelectColor('Text', null);"
+          observes="cmd_fontColor"
+          oncommand="goDoCommand('cmd_fontColor')"
           position="4"/>
     <menuseparator position="5"/>
 
@@ -457,18 +469,18 @@
           accesskey="&formatparagraphmenu.accesskey;"
           position="9" oncreate="InitParagraphMenu()">
       <menupopup oncommand="doStatefulCommand('cmd_paragraphState', event.target.getAttribute('value'))">
-        <menuitem id="menu_bodyText"  type="radio" name="1" label="&bodyTextCmd.label;"             accesskey="&bodytext.accesskey;"              value=""/>
-        <menuitem id="menu_p"         type="radio" name="1" label="&paragraphParagraphCmd.label;"   accesskey="&paragraphparagraph.accesskey;"  value="p"/>
-        <menuitem id="menu_h1"        type="radio" name="1" label="&heading1Cmd.label;"             accesskey="&heading1.accesskey;"            value="h1"/>
-        <menuitem id="menu_h2"        type="radio" name="1" label="&heading2Cmd.label;"             accesskey="&heading2.accesskey;"            value="h2"/>
-        <menuitem id="menu_h3"        type="radio" name="1" label="&heading3Cmd.label;"             accesskey="&heading3.accesskey;"            value="h3"/>
-        <menuitem id="menu_h4"        type="radio" name="1" label="&heading4Cmd.label;"             accesskey="&heading4.accesskey;"            value="h4"/>
-        <menuitem id="menu_h5"        type="radio" name="1" label="&heading5Cmd.label;"             accesskey="&heading5.accesskey;"            value="h5"/>
-        <menuitem id="menu_h6"        type="radio" name="1" label="&heading6Cmd.label;"             accesskey="&heading6.accesskey;"            value="h6"/>
-        <menuitem id="menu_address"   type="radio" name="1" label="&paragraphAddressCmd.label;"     accesskey="&paragraphaddress.accesskey;"    value="address"/>   
-        <menuitem id="menu_pre"       type="radio" name="1" label="&paragraphPreformatCmd.label;"   accesskey="&paragraphpreformat.accesskey;"  value="pre"/>       
+        <menuitem id="menu_bodyText"  type="radio" name="1" label="&bodyTextCmd.label;"             accesskey="&bodytext.accesskey;"            value=""      observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_p"         type="radio" name="1" label="&paragraphParagraphCmd.label;"   accesskey="&paragraphparagraph.accesskey;"  value="p"     observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_h1"        type="radio" name="1" label="&heading1Cmd.label;"             accesskey="&heading1.accesskey;"            value="h1"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_h2"        type="radio" name="1" label="&heading2Cmd.label;"             accesskey="&heading2.accesskey;"            value="h2"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_h3"        type="radio" name="1" label="&heading3Cmd.label;"             accesskey="&heading3.accesskey;"            value="h3"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_h4"        type="radio" name="1" label="&heading4Cmd.label;"             accesskey="&heading4.accesskey;"            value="h4"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_h5"        type="radio" name="1" label="&heading5Cmd.label;"             accesskey="&heading5.accesskey;"            value="h5"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_h6"        type="radio" name="1" label="&heading6Cmd.label;"             accesskey="&heading6.accesskey;"            value="h6"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_address"   type="radio" name="1" label="&paragraphAddressCmd.label;"     accesskey="&paragraphaddress.accesskey;"    value="address"  observes="cmd_renderedHTMLEnabler"/>   
+        <menuitem id="menu_pre"       type="radio" name="1" label="&paragraphPreformatCmd.label;"   accesskey="&paragraphpreformat.accesskey;"  value="pre"   observes="cmd_renderedHTMLEnabler"/>       
         <menuseparator/>
-        <menuitem id="menu_blockquote" type="checkbox" label="&paragraphBlockquoteCmd.label;"  accesskey="&paragraphblockquote.accesskey;" value="blockquote"/>
+        <menuitem id="menu_blockquote" type="checkbox" label="&paragraphBlockquoteCmd.label;"  accesskey="&paragraphblockquote.accesskey;" value="blockquote" observes="cmd_renderedHTMLEnabler"/>
       </menupopup>
     </menu>
 
@@ -498,10 +510,10 @@
         position="14">
       <!-- Align submenu -->
       <menupopup oncommand="doStatefulCommand('cmd_align', event.target.getAttribute('value'))">
-        <menuitem id="menu_left"    label="&alignLeft.label;"  accesskey="&alignleft.accesskey;"      type="radio" name="1" value="left"/>
-        <menuitem id="menu_center"  label="&alignCenter.label;"  accesskey="&aligncenter.accesskey;"  type="radio" name="1" value="center"/>
-        <menuitem id="menu_right"   label="&alignRight.label;"   accesskey="&alignright.accesskey;"   type="radio" name="1" value="right"/>
-        <menuitem id="menu_justify" label="&alignJustify.label;" accesskey="&alignjustify.accesskey;" type="radio" name="1" value="justify"/>
+        <menuitem id="menu_left"    label="&alignLeft.label;"  accesskey="&alignleft.accesskey;"      type="radio" name="1" value="left"    observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_center"  label="&alignCenter.label;"  accesskey="&aligncenter.accesskey;"  type="radio" name="1" value="center"  observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_right"   label="&alignRight.label;"   accesskey="&alignright.accesskey;"   type="radio" name="1" value="right"   observes="cmd_renderedHTMLEnabler"/>
+        <menuitem id="menu_justify" label="&alignJustify.label;" accesskey="&alignjustify.accesskey;" type="radio" name="1" value="justify" observes="cmd_renderedHTMLEnabler"/>
       </menupopup>
     </menu>
     <menuseparator position="15"/>
@@ -511,15 +523,12 @@
 
   <!-- Next 3 are items to append at the bottom of the formatMenuPopup -->
   <!-- label and accesskey filled in during menu creation -->
-  <menuitem id="objectProperties" 
-            oncommand="goDoCommand('cmd_objectProperties')"/>
+  <menuitem id="objectProperties"   oncommand="goDoCommand('cmd_objectProperties')"   observes="cmd_renderedHTMLEnabler"/>
   <!-- Dont use 'observes', must call command correctly -->
-  <menuitem id="pageProperties" label="&pageProperties.label;"
-            accesskey="&pageproperties.accesskey;"
-            oncommand="goDoCommand('cmd_pageProperties')"/>
-  <menuitem id="colorsAndBackground" label="&colorsAndBackground.label;"
-            accesskey="&colorsandbackground.accesskey;"
-            oncommand="goDoCommand('cmd_colorProperties')"/>
+  <menuitem id="pageProperties"       label="&pageProperties.label;"       accesskey="&pageproperties.accesskey;"      
+            oncommand="goDoCommand('cmd_pageProperties')"  observes="cmd_renderedHTMLEnabler"/>
+  <menuitem id="colorsAndBackground"  label="&colorsAndBackground.label;"  accesskey="&colorsandbackground.accesskey;"
+            oncommand="goDoCommand('cmd_colorProperties')" observes="cmd_renderedHTMLEnabler"/>
 
   <menu id="tableMenu" label="&tableMenu.label;" accesskey="&tablemenu.accesskey;">
     <menupopup  oncreate="EditorInitTableMenu()">