Sorry to hear that but if you have problem with update firefox the better way is to download and install the new version. 1. Download a new copy of the Firefox program 2. Firefox 11.0 from: http://www.mozilla.org/en-US/firefox/all.html 3. '''Trash''' the current Firefox application to do a clean install. 4. Install the new version that you have downloaded. Your profile data is stored elsewhere in the [http://kb.mozillazine.org/Profile_folder_-_Firefox Firefox Profile Folder], so you won't lose your bookmarks or other personal data. see also: [https://support.mozilla.org/en-US/kb/Installing%20Firefox%20on%20Mac Installing Firefox on Mac] thank you Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.