Can you attach a screenshot? *http://en.wikipedia.org/wiki/Screenshot *https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem Use a compressed image type like PNG or JPG to save the screenshot. Try to 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) Try to repair the disk permissions: *http://thexlab.com/faqs/repairprocess.html You can also check for problems with the localstore.rdf file. *http://kb.mozillazine.org/Corrupt_localstore.rdf *https://support.mozilla.org/kb/Toolbar+keeps+resetting