--- a/editor/ui/composer/content/ComposerCommands.js
+++ b/editor/ui/composer/content/ComposerCommands.js
@@ -1344,16 +1344,26 @@ var gEditorOutputProgressListener =
     var promptServ = GetPromptService();
     if (!promptServ)
      return 0;
 
     return promptServ.confirmEx(window, dlgTitle, text, btnFlags,
                         btn0Title, btn1Title, btn2Title,
                         checkBoxLabel, checkVal);
   },
+
+  /*************************************************************************
+   * gEditorOutputProgressListener needs to implement both nsIPrompt       *
+   * (providing alert) and nsIAuthPrompt (providing password saving).      *
+   * Unfortunately, both interfaces specify prompt/promptPassword/         *
+   * promptUsernameAndPassword, albeit with conflicting method signatures. *
+   * Luckily, though, we only make use of their nsIAuthPrompt variants,    *
+   * hence we can comment out the nsIPrompt ones here to avoid JavaScript  *
+   * strict mode clutter. See bug 371174 for more information.             *
+   *************************************************************************
   prompt : function(dlgTitle, text, inoutText, checkBoxLabel, checkObj)
   {
     var promptServ = GetPromptService();
     if (!promptServ)
      return false;
 
     return promptServ.prompt(window, dlgTitle, text, inoutText, checkBoxLabel, checkObj);
   },
@@ -1387,16 +1397,18 @@ var gEditorOutputProgressListener =
   promptUsernameAndPassword : function(dlgTitle, text, userObj, pwObj, checkBoxLabel, savePWObj)
   {
     var ret = PromptUsernameAndPassword(dlgTitle, text, savePWObj.value, userObj, pwObj);
     if (!ret)
       setTimeout(CancelPublishing, 0);
 
     return ret;
   },
+   *************************************************************************/
+
   select : function(dlgTitle, text, count, selectList, outSelection)
   {
     var promptServ = GetPromptService();
     if (!promptServ)
       return false;
 
     return promptServ.select(window, dlgTitle, text, count, selectList, outSelection);
   },