diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 0147721aa4b8..41e2530d9d35 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -305,9 +305,10 @@ pref("javascript.options.showInConsole",          false);
 pref("dom.disable_window_open_feature.status",    true);
 // This is the pref to control the location bar, change this to true to 
 // force this instead of or in addition to the status bar - this makes 
-// the origin of popup windows more obvious to avoid spoofing but we 
-// cannot do it by default because it affects UE for web applications.
-pref("dom.disable_window_open_feature.location",  false);
+// the origin of popup windows more obvious to avoid spoofing. We would 
+// rather not do it by default because it affects UE for web applications, but
+// without it there isn't a really good way to prevent chrome spoofing, see bug 337344
+pref("dom.disable_window_open_feature.location",  true);
 pref("dom.disable_window_status_change",          true);
 // allow JS to move and resize existing windows
 pref("dom.disable_window_move_resize",            false);
diff --git a/browser/components/nsBrowserContentHandler.js b/browser/components/nsBrowserContentHandler.js
index 38c8b36bdcb8..3cc8bea8bbfc 100644
--- a/browser/components/nsBrowserContentHandler.js
+++ b/browser/components/nsBrowserContentHandler.js
@@ -221,12 +221,12 @@ function getMostRecentBrowserWindow() {
   var win = wm.getMostRecentWindow("navigator:browser", true);
 
   // if we're lucky, this isn't a popup, and we can just return this
-  if (win && !win.toolbar.visible) {
+  if (win && win.document.documentElement.getAttribute("chromehidden")) {
     var windowList = wm.getEnumerator("navigator:browser", true);
     // this is oldest to newest, so this gets a bit ugly
     while (windowList.hasMoreElements()) {
       var nextWin = windowList.getNext();
-      if (nextWin.toolbar.visible)
+      if (!nextWin.document.documentElement.getAttribute("chromehidden"))
         win = nextWin;
     }
   }
@@ -236,7 +236,7 @@ function getMostRecentBrowserWindow() {
     return null;
 
   var win = windowList.getNext();
-  while (!win.toolbar.visible) {
+  while (win.document.documentElement.getAttribute("chromehidden")) {
     if (!windowList.hasMoreElements()) 
       return null;