Do you mean that you only get the Firefox menu bar? You can check for problems caused by a corrupted localstore.rdf file. *http://kb.mozillazine.org/Corrupt_localstore.rdf You can also try these: Remove the Firefox plist file (org.mozilla.firefox.plist). *http://www.macfixit.com/article.php?story=20060606082246983 How .plist files become corrupt and troubleshooting the results Go to "~/Library/Preferences" and remove the plist file for Firefox (org.mozilla.firefox.plist) Repair the disk permissions: *http://thexlab.com/faqs/repairprocess.html