diff --git a/widget/src/cocoa/nsCocoaTextInputHandler.h b/widget/src/cocoa/nsCocoaTextInputHandler.h
index 98f1e65f3f6..5ffb5be9289 100644
--- a/widget/src/cocoa/nsCocoaTextInputHandler.h
+++ b/widget/src/cocoa/nsCocoaTextInputHandler.h
@@ -259,6 +259,10 @@ public:
   static CFArrayRef CreateAllIMEModeList();
   static void DebugPrintAllIMEModes(PRLogModuleInfo* aLogModuleInfo);
 
+  // Don't use ::TSMGetActiveDocument() API directly, the document may not
+  // be what you want.
+  static TSMDocumentID GetCurrentTSMDocumentID();
+
 protected:
   // The owner of this instance.  The result of mOwnerWidget->TextInputHandler
   // returns this instance.  This must not be null after initialized.
diff --git a/widget/src/cocoa/nsCocoaTextInputHandler.mm b/widget/src/cocoa/nsCocoaTextInputHandler.mm
index cbb9b3c2af8..3fa779bd07d 100644
--- a/widget/src/cocoa/nsCocoaTextInputHandler.mm
+++ b/widget/src/cocoa/nsCocoaTextInputHandler.mm
@@ -682,6 +682,17 @@ nsCocoaIMEHandler::DebugPrintAllIMEModes(PRLogModuleInfo* aLogModuleInfo)
   ::CFRelease(list);
 }
 
+//static
+TSMDocumentID
+nsCocoaIMEHandler::GetCurrentTSMDocumentID()
+{
+  // On OS X 10.6.x at least, ::TSMGetActiveDocument() has a bug that prevents
+  // it from returning accurate results unless
+  // [NSInputManager currentInputManager] is called first.
+  // So, we need to call [NSInputManager currentInputManager] first here.
+  [NSInputManager currentInputManager];
+  return ::TSMGetActiveDocument();
+}
 
 #pragma mark -
 
@@ -706,8 +717,8 @@ nsCocoaIMEHandler::ResetIMEWindowLevel()
 #ifdef DEBUG_IME_HANDLER
   DebugPrintPointer(this);
   NSLog(@"nsCocoaIMEHandler::ResetIMEWindowLevel");
-  NSLog(@"  IsFocused:%s ::TSMGetActiveDocument():%p",
-        TrueOrFalse(IsFocused()), ::TSMGetActiveDocument());
+  NSLog(@"  IsFocused:%s GetCurrentTSMDocumentID():%p",
+        TrueOrFalse(IsFocused()), GetCurrentTSMDocumentID());
 #endif // DEBUG_IME_HANDLER
 
   if (!mView)
@@ -719,7 +730,7 @@ nsCocoaIMEHandler::ResetIMEWindowLevel()
     return;
   }
 
-  TSMDocumentID doc = ::TSMGetActiveDocument();
+  TSMDocumentID doc = GetCurrentTSMDocumentID();
   if (!doc) {
     // retry
     mPendingMethods |= kResetIMEWindowLevel;
@@ -752,7 +763,7 @@ nsCocoaIMEHandler::ResetIMEWindowLevel()
   if (windowLevel == NSNormalWindowLevel)
     windowLevel++;
 
-  ::TSMSetDocumentProperty(::TSMGetActiveDocument(),
+  ::TSMSetDocumentProperty(GetCurrentTSMDocumentID(),
                            kTSMDocumentWindowLevelPropertyTag,
                            sizeof(windowLevel), &windowLevel);
 
@@ -803,8 +814,8 @@ nsCocoaIMEHandler::SyncASCIICapableOnly()
 #ifdef DEBUG_IME_HANDLER
   DebugPrintPointer(this);
   NSLog(@"nsCocoaIMEHandler::SyncASCIICapableOnly");
-  NSLog(@"  IsFocused:%s ::TSMGetActiveDocument():%p",
-        TrueOrFalse(IsFocused()), ::TSMGetActiveDocument());
+  NSLog(@"  IsFocused:%s GetCurrentTSMDocumentID():%p",
+        TrueOrFalse(IsFocused()), GetCurrentTSMDocumentID());
 #endif
 
   if (!mView)
@@ -816,7 +827,7 @@ nsCocoaIMEHandler::SyncASCIICapableOnly()
     return;
   }
 
-  TSMDocumentID doc = ::TSMGetActiveDocument();
+  TSMDocumentID doc = GetCurrentTSMDocumentID();
   if (!doc) {
     // retry
     mPendingMethods |= kSyncASCIICapableOnly;
@@ -847,12 +858,9 @@ nsCocoaIMEHandler::ResetTimer()
                "There are not pending methods, why this is called?");
   if (mTimer) {
     mTimer->Cancel();
-    return;
-  }
-  mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
-  if (!mTimer) {
-    NS_ERROR("mTimer is null");
-    return;
+  } else {
+    mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+    NS_ENSURE_TRUE(mTimer, );
   }
   mTimer->InitWithFuncCallback(FlushPendingMethods, this, 0,
                                nsITimer::TYPE_ONE_SHOT);
@@ -863,6 +871,11 @@ nsCocoaIMEHandler::ExecutePendingMethods()
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
+  if (mTimer) {
+    mTimer->Cancel();
+    mTimer = nsnull;
+  }
+
   if (![[NSApplication sharedApplication] isActive]) {
     mIsInFocusProcessing = PR_FALSE;
     // If we're not active, we should retry at focus event
@@ -873,10 +886,6 @@ nsCocoaIMEHandler::ExecutePendingMethods()
   // First, reset the pending method flags because if each methods cannot
   // run now, they can reentry to the pending flags by theirselves.
   mPendingMethods = 0;
-  if (mTimer) {
-    mTimer->Cancel();
-    mTimer = nsnull;
-  }
 
   if (pendingMethods & kDiscardIMEComposition)
     DiscardIMEComposition();
@@ -1164,7 +1173,8 @@ nsCocoaIMEHandler::IsFocused()
   NS_ENSURE_TRUE(mView, PR_FALSE);
   NSWindow* window = [mView window];
   NS_ENSURE_TRUE(window, PR_FALSE);
-  return [window firstResponder] == mView && [window isMainWindow] &&
+  return [window firstResponder] == mView &&
+         ([window isMainWindow] || [window isSheet]) &&
          [[NSApplication sharedApplication] isActive];
 
   NS_OBJC_END_TRY_ABORT_BLOCK_RETURN(PR_FALSE);
diff --git a/widget/tests/test_imestate.html b/widget/tests/test_imestate.html
index 44a02f3af16..4a1e212961c 100644
--- a/widget/tests/test_imestate.html
+++ b/widget/tests/test_imestate.html
@@ -861,6 +861,79 @@ function runEditableSubframeTests()
               "width=600,height=600");
 }
 
+function runTestPasswordFieldOnDialog()
+{
+  if (!kIMEEnabledSupported) {
+    return;
+  }
+
+  if (document.activeElement) {
+    document.activeElement.blur();
+  }
+
+  var dialog;
+
+  function WindowObserver()
+  {
+    Components.classes["@mozilla.org/observer-service;1"].
+               getService(Components.interfaces.nsIObserverService).
+               addObserver(this, "domwindowopened", false);
+  }
+
+  WindowObserver.prototype = {
+    QueryInterface: function (iid)
+    {
+      if (iid.equals(Components.interfaces.nsIObserver) ||
+          iid.equals(Components.interfaces.nsISupports)) {
+        return this;
+      }
+    },
+
+    observe: function (subject, topic, data)
+    {
+      if (topic === "domwindowopened") {
+        ok(true, "dialog window is created");
+        dialog = subject.QueryInterface(Components.interfaces.nsIDOMWindow);
+        dialog.addEventListener("load", onPasswordDialogLoad, false);
+      }
+    }
+  };
+
+  var observer = new WindowObserver();
+  var arg1 = new Object(), arg2 = new Object();
+  Components.classes["@mozilla.org/embedcomp/prompt-service;1"].
+             getService(Components.interfaces.nsIPromptService).
+             promptPassword(window, "title", "text", arg1, "msg", arg2);
+
+  ok(true, "password dialog was closed");
+
+  Components.classes["@mozilla.org/observer-service;1"].
+             getService(Components.interfaces.nsIObserverService).
+             removeObserver(observer, "domwindowopened");
+
+  var passwordField;
+
+  function onPasswordDialogLoad()
+  {
+    ok(true, "onPasswordDialogLoad is called");
+    dialog.removeEventListener("load", onPasswordDialogLoad, false);
+    passwordField = dialog.document.getElementById("password1Textbox");
+    passwordField.addEventListener("focus", onPasswordFieldFocus, false);
+  }
+
+  function onPasswordFieldFocus()
+  {
+    ok(true, "onPasswordFieldFocus is called");
+    passwordField.removeEventListener("focus", onPasswordFieldFocus, false);
+    var utils = dialog.
+      QueryInterface(Components.interfaces.nsIInterfaceRequestor).
+      getInterface(Components.interfaces.nsIDOMWindowUtils);
+    is(utils.IMEStatus, utils.IME_STATUS_PASSWORD,
+       "IME isn't disabled on a password field of password dialog");
+    synthesizeKey("VK_ESCAPE", { }, dialog);
+  }
+}
+
 function runTests()
 {
   if (!kIMEEnabledSupported && !kIMEOpenSupported)
@@ -908,6 +981,9 @@ function runTests()
   // test whether the IME state and composition are not changed unexpectedly
   runEditorFlagChangeTests();
 
+  // test password field on dialog
+  runTestPasswordFieldOnDialog();
+
   runASyncTests();
 }