Do a clean reinstall.

Download a fresh Firefox copy and save the file to the desktop.

• Firefox 5.0.x: http://www.mozilla.com/en-US/firefox/all.html

• Uninstall your current Firefox version.
• Do not remove personal data when you uninstall the current version.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.

Your bookmarks and other profile data are stored elsewhere in the Firefox Profile Folder and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

Thanks! that was a bit over my head, but i think i pulled it off! I really appreciate your response. I am not sure how to delete the program folder after uninstalling the previous version... i just went ahead and installed the new one. Does the program folder delete when the program is uninstalled?

Not, necessarily. It is possible that some files can't be removed for some reason (e.g. locked by security software) and in that case you need to remove the Firefox program folder (C:\Program Files\Mozilla Firefox\) yourself manually top remove all files and to avoid the problem from reappearing.