diff -up firefox-4.0/mozilla-central/browser/components/preferences/advanced.xul.default firefox-4.0/mozilla-central/browser/components/preferences/advanced.xul
--- firefox-4.0/mozilla-central/browser/components/preferences/advanced.xul.default	2010-08-06 03:08:58.000000000 +0200
+++ firefox-4.0/mozilla-central/browser/components/preferences/advanced.xul	2010-08-30 16:35:21.000000000 +0200
@@ -183,10 +183,11 @@
           </groupbox>
 
 #ifdef HAVE_SHELL_SERVICE
+#ifdef MOZ_CRASHREPORTER
           <!-- System Defaults -->
           <groupbox id="systemDefaultsGroup" orient="vertical">
             <caption label="&systemDefaults.label;"/>
-
+#ifdef 0
             <hbox id="checkDefaultBox" align="center" flex="1">      
               <checkbox id="alwaysCheckDefault" preference="browser.shell.checkDefaultBrowser"
                         label="&alwaysCheckDefault.label;" accesskey="&alwaysCheckDefault.accesskey;"
@@ -196,6 +197,7 @@
                       oncommand="gAdvancedPane.checkNow()"
                       preference="pref.general.disable_button.default_browser"/>
             </hbox>
+#endif
 #ifdef MOZ_CRASHREPORTER
             <checkbox id="submitCrashesBox" flex="1"
                       oncommand="gAdvancedPane.updateSubmitCrashes();"
@@ -203,6 +205,7 @@
 #endif
           </groupbox>
 #endif
+#endif
         </tabpanel>
 
         <!-- Network -->
diff -up firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.cpp.default firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.cpp
--- firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.cpp.default	2010-08-06 03:08:59.000000000 +0200
+++ firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.cpp	2010-08-30 16:37:41.000000000 +0200
@@ -140,27 +140,21 @@ NS_IMPL_ISUPPORTS1(nsGNOMEShellService, 
 PRBool
 nsGNOMEShellService::KeyMatchesAppName(const char *aKeyValue) const
 {
+  nsCAutoString appName;
 
-  gchar *commandPath;
   if (mUseLocaleFilenames) {
     gchar *nativePath = g_filename_from_utf8(aKeyValue, -1, NULL, NULL, NULL);
     if (!nativePath) {
       NS_ERROR("Error converting path to filesystem encoding");
       return PR_FALSE;
     }
-
-    commandPath = g_find_program_in_path(nativePath);
+    appName.Assign(nativePath);
     g_free(nativePath);
   } else {
-    commandPath = g_find_program_in_path(aKeyValue);
+    appName.Assign(aKeyValue);
   }
-
-  if (!commandPath)
-    return PR_FALSE;
-
-  PRBool matches = mAppPath.Equals(commandPath);
-  g_free(commandPath);
-  return matches;
+  // Compare default browser command retrieved from gconf with MOZ_APP_NAME
+  return appName.EqualsLiteral(MOZ_APP_NAME);
 }
 
 NS_IMETHODIMP
@@ -215,8 +209,8 @@ nsGNOMEShellService::SetDefaultBrowser(P
 
   nsCOMPtr<nsIGConfService> gconf = do_GetService(NS_GCONFSERVICE_CONTRACTID);
 
-  nsCAutoString appKeyValue(mAppPath);
-  appKeyValue.Append(" \"%s\"");
+  nsCAutoString appKeyValue(MOZ_APP_NAME);
+  appKeyValue.Append(" %s");
   unsigned int i;
 
   for (i = 0; i < NS_ARRAY_LENGTH(appProtocols); ++i) {
diff -up firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.h.default firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.h
--- firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.h.default	2010-08-06 03:08:59.000000000 +0200
+++ firefox-4.0/mozilla-central/browser/components/shell/src/nsGNOMEShellService.h	2010-08-30 16:35:22.000000000 +0200
@@ -43,7 +43,7 @@
 class nsGNOMEShellService : public nsIShellService
 {
 public:
-  nsGNOMEShellService() : mCheckedThisSession(PR_FALSE) { }
+  nsGNOMEShellService() : mCheckedThisSession(PR_TRUE) { }
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSISHELLSERVICE