diff --git a/mozilla/toolkit/content/contentAreaUtils.js b/mozilla/toolkit/content/contentAreaUtils.js
index 328bed644a6..d2c2bc3f601 100644
--- a/mozilla/toolkit/content/contentAreaUtils.js
+++ b/mozilla/toolkit/content/contentAreaUtils.js
@@ -884,14 +884,15 @@ function getNormalizedLeafName(aFile, aDefaultExtension)
 {
   if (!aDefaultExtension)
     return aFile;
-  
+
+#ifdef XP_WIN
+  // Remove trailing dots and spaces on windows
+  aFile = aFile.replace(/[\s.]+$/, "");
+#endif
+      
   // Fix up the file name we're saving to to include the default extension
-  const stdURLContractID = "@mozilla.org/network/standard-url;1";
-  const stdURLIID = Components.interfaces.nsIURL;
-  var url = Components.classes[stdURLContractID].createInstance(stdURLIID);
-  url.filePath = aFile;
-  
-  if (url.fileExtension != aDefaultExtension)
+  var i = aFile.lastIndexOf(".");
+  if (aFile.substr(i + 1) != aDefaultExtension)
     return aFile + "." + aDefaultExtension;
 
   return aFile;