same thing.

browser/base/content/browser.js

@@ -277,9 +277,6 @@ function Startup()
     uriToLoad = window.arguments[0];
   gIsLoadingBlank = uriToLoad == "about:blank";
 
-  // Initialize browser instance..
-  appCore.setWebShellWindow(window);
-
   if (!gIsLoadingBlank) {
     prepareForStartup();
   }
@@ -365,6 +362,9 @@ function prepareForStartup()
     }
   }
 
+  // Initialize browser instance..
+  appCore.setWebShellWindow(window);
+
   // Wire up session and global history before any possible
   // progress notifications for back/forward button updating
   getWebNavigation().sessionHistory = Components.classes["@mozilla.org/browser/shistory;1"]