diff --git a/dom/locales/en-US/chrome/prompts.properties b/dom/locales/en-US/chrome/prompts.properties
index 135d06a9256..078807924db 100644
--- a/dom/locales/en-US/chrome/prompts.properties
+++ b/dom/locales/en-US/chrome/prompts.properties
@@ -34,8 +34,13 @@
 #
 # ***** END LICENSE BLOCK *****
 
-EnterUserPasswordForRealm=Enter username and password for "%1$S" at %2$S
-EnterUserPasswordForProxy=Enter username and password for proxy "%1$S" at %2$S
+# Localizer note: %1 is an untrusted string provided by a remote server. It
+# could try to take advantage of sentence structure in order to mislead the
+# user (see bug 244273). It should be integrated into the these property
+# strings as little as possible.
+EnterLoginForRealm=A username and password are being requested by %2$S. The site says: "%1$S"
+EnterLoginForProxy=The proxy %2$S is requesting a username and password. The site says: "%1$S"
+
 EnterUserPasswordFor=Enter username and password for %1$S
 EnterPasswordFor=Enter password for %1$S on %2$S
 
diff --git a/embedding/components/windowwatcher/src/nsPrompt.cpp b/embedding/components/windowwatcher/src/nsPrompt.cpp
index f95e19ed7c9..a782689cc85 100644
--- a/embedding/components/windowwatcher/src/nsPrompt.cpp
+++ b/embedding/components/windowwatcher/src/nsPrompt.cpp
@@ -55,6 +55,9 @@
 #include "nsIIDNService.h"
 #include "nsNetUtil.h"
 #include "nsPromptUtils.h"
+#include "nsIPrefService.h"
+#include "nsIPrefLocalizedString.h"
+
 
 nsresult
 NS_NewPrompter(nsIPrompt **result, nsIDOMWindow *aParent)
@@ -418,6 +421,26 @@ MakeDialogText(nsIChannel* aChannel, nsIAuthInformation* aAuthInfo,
 
   nsAutoString realm;
   aAuthInfo->GetRealm(realm);
+  // Trim obnoxiously long realms.
+  if (realm.Length() > 150) {
+    realm.Truncate(150);
+
+    // Append "..." (or localized equivalent). Yay complexity.
+    nsAutoString ellipsis;
+    nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
+    if (prefs) {
+      nsCOMPtr<nsIPrefLocalizedString> prefString;
+      rv = prefs->GetComplexValue("intl.ellipsis",
+                                  NS_GET_IID(nsIPrefLocalizedString),
+                                  getter_AddRefs(prefString));
+      if (prefString)
+        prefString->ToString(getter_Copies(ellipsis));
+    }
+    if (ellipsis.IsEmpty())
+      ellipsis.AssignLiteral("...");
+
+    realm.Append(ellipsis);
+  }
 
   // Append the port if it was specified
   if (port != -1) {
@@ -425,8 +448,8 @@ MakeDialogText(nsIChannel* aChannel, nsIAuthInformation* aAuthInfo,
     displayHost.AppendInt(port);
   }
 
-  NS_NAMED_LITERAL_STRING(proxyText, "EnterUserPasswordForProxy");
-  NS_NAMED_LITERAL_STRING(originText, "EnterUserPasswordForRealm");
+  NS_NAMED_LITERAL_STRING(proxyText, "EnterLoginForProxy");
+  NS_NAMED_LITERAL_STRING(originText, "EnterLoginForRealm");
   NS_NAMED_LITERAL_STRING(noRealmText, "EnterUserPasswordFor");
   NS_NAMED_LITERAL_STRING(passwordText, "EnterPasswordFor");
 
diff --git a/toolkit/content/commonDialog.css b/toolkit/content/commonDialog.css
index 73e5418c5c9..8732dc7c3ed 100644
--- a/toolkit/content/commonDialog.css
+++ b/toolkit/content/commonDialog.css
@@ -37,9 +37,18 @@
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* set default namespace to XUL */
 
-#info\.box > description {
+#infoContainer {
+  max-width: 45em;
+}
+
+#info\.body {
   -moz-user-focus: normal;
   -moz-user-select: text;
   cursor: text !important;
   white-space: -moz-pre-wrap;
 }
+
+#loginLabel, #password1Label, #password2Label {
+  text-align: right;
+}
+
diff --git a/toolkit/content/commonDialog.js b/toolkit/content/commonDialog.js
index 4d1eac59121..2f3cfa5304a 100644
--- a/toolkit/content/commonDialog.js
+++ b/toolkit/content/commonDialog.js
@@ -124,9 +124,9 @@ function commonDialogOnLoad()
   }
 
   // display the main text
-  var messageParent = document.getElementById("info.box").getElementsByTagName('description')[0];
   // XXX the substr(0, 10000) part is a workaround for bug 317334
-  messageParent.textContent = gCommonDialogParam.GetString(0).substr(0, 10000);
+  var croppedMessage = gCommonDialogParam.GetString(0).substr(0, 10000);
+  setElementText("info.body", croppedMessage, true);
 
   setElementText("info.header", gCommonDialogParam.GetString(3), true);
 
@@ -262,9 +262,7 @@ function setElementText(aElementID, aValue, aChildNodeFlag)
 function setCheckbox(aChkMsg, aChkValue)
 {
   if (aChkMsg) {
-    // XXX Would love to use hidden instead of collapsed, but the checkbox
-    // fails to size itself properly when I do this.
-    document.getElementById("checkboxContainer").removeAttribute("collapsed");
+    unHideElementById("checkboxContainer");
     
     var checkboxElement = document.getElementById("checkbox");
     setLabelForNode(checkboxElement, aChkMsg);
diff --git a/toolkit/content/commonDialog.xul b/toolkit/content/commonDialog.xul
index a2d12efd472..df05687978a 100644
--- a/toolkit/content/commonDialog.xul
+++ b/toolkit/content/commonDialog.xul
@@ -38,46 +38,46 @@
     </popup>
   </popupset>
 
-  <hbox flex="1">
-    <hbox align="start">
-      <image id="info.icon" class="spaced"/>
-    </hbox>
-    
-    <vbox flex="1" style="max-width: 45em;">
-#ifdef XP_MACOSX
-# On mac, we're exposing the dialog title inside the dialog
-      <!-- Dialog title -->
-      <description id="info.title" class="dialogTitle"/>
-#endif
-      <!-- text -->
-      <description id="info.header" class="header"/>
-      <vbox id="info.box">
-        <description context="contentAreaContextMenu" tabindex="-1"/>
-      </vbox>
 
-      <!-- textboxes -->
-      <vbox id="loginContainer" hidden="true">
+  <grid>
+    <columns>
+      <column/>
+      <column flex="1"/>
+    </columns>
+
+    <rows>
+      <row>
+        <hbox align="start">
+          <image id="info.icon" class="spaced"/>
+        </hbox>
+        <vbox id="infoContainer">
+#ifdef XP_MACOSX
+          <!-- Dialog title is inside dialog for OS X -->
+          <description id="info.title" class="dialogTitle"/>
+#endif
+          <description id="info.header" class="header"/>
+          <description id="info.body" context="contentAreaContextMenu" tabindex="-1"/>
+        </vbox>
+      </row>
+      <row id="loginContainer" hidden="true" align="center">
         <label id="loginLabel" value="&editfield0.label;" control="loginTextbox"/>
         <textbox id="loginTextbox"/>
-        <separator class="thin"/>
-      </vbox>
-      <vbox id ="password1Container" hidden="true">
+      </row>
+      <row id ="password1Container" hidden="true" align="center">
         <label id="password1Label" value="&editfield1.label;" control="password1Textbox"/>
         <textbox type="password" id="password1Textbox"/>
-        <separator class="thin"/>
-      </vbox>
-      <vbox id="password2Container" hidden="true">
+      </row>
+      <row id="password2Container" hidden="true" align="center">
         <label id="password2Label" value="&editfield2.label;" control="password2Textbox"/>
         <textbox type="password" id="password2Textbox"/>
-        <separator class="thin"/>
-      </vbox>
-  
-      <!-- checkbox -->
-      <vbox id="checkboxContainer" align="start" collapsed="true">
+      </row>
+      <row id="checkboxContainer" hidden="true">
+        <spacer/>
         <checkbox id="checkbox" oncommand="onCheckboxClick(this);"/>
-      </vbox>
-    </vbox>
-  </hbox>
+      </row>
+    </rows>
+  </grid>
+
 
   <!-- This method is called inline because it may unset hidden="true" on the
        above boxes, causing their frames to be build and bindings to load.  
diff --git a/toolkit/themes/pinstripe/global/formatting.css b/toolkit/themes/pinstripe/global/formatting.css
index 0f99a2508f1..b3b18b96d6a 100644
--- a/toolkit/themes/pinstripe/global/formatting.css
+++ b/toolkit/themes/pinstripe/global/formatting.css
@@ -189,7 +189,9 @@
       margin: 0px 2px 0px 1px !important;
     }
 
-#commonDialog > hbox > vbox > description, #commonDialog > hbox > vbox > vbox > description {
+#commonDialog #info\.title,
+#commonDialog #info\.header,
+#commonDialog #info\.body {
   font: menu;
   line-height: 16px;
   margin-bottom: 6px;
diff --git a/toolkit/themes/pinstripe/global/global.css b/toolkit/themes/pinstripe/global/global.css
index 46b142d6144..4cd23ec239e 100644
--- a/toolkit/themes/pinstripe/global/global.css
+++ b/toolkit/themes/pinstripe/global/global.css
@@ -186,7 +186,7 @@ statusbarpanel {
 	line-height: 13px;
 }
 
-#commonDialog > hbox > vbox {
+#commonDialog #infoContainer {
 	max-width: 33em !important;
 }