diff -up firefox-21.0/mozilla-release/toolkit/mozapps/installer/packager.py.old firefox-21.0/mozilla-release/toolkit/mozapps/installer/packager.py
--- firefox-21.0/mozilla-release/toolkit/mozapps/installer/packager.py.old	2013-05-15 08:27:23.000000000 +0200
+++ firefox-21.0/mozilla-release/toolkit/mozapps/installer/packager.py	2013-05-15 08:27:54.828483740 +0200
@@ -344,7 +344,7 @@ def main():
     # Fill startup cache
     if isinstance(formatter, OmniJarFormatter) and launcher.can_launch():
         if buildconfig.substs['LIBXUL_SDK']:
-            gre_path = buildconfig.substs['LIBXUL_DIST']
+            gre_path = buildconfig.substs['LIBXUL_DIST'] + '/bin'
         else:
             gre_path = None
         for base in sorted([[p for p in [mozpack.path.join('bin', b), b]