Try to repair the disk permissions:

• http://thexlab.com/faqs/repairprocess.html
• http://guides.macrumors.com/Repairing_Permissions

You can also 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).

Now I can get to pulldown menus. But Firefox is still hanging if I leave it alone for too long.

I repaired disk permissions. I also turned this machine into an external hard drive and used another to repair the disk. Neither helped. I also ran Drive Genius 2 in my machine to repair permissions. Didn't make a difference. Then I turned this machine into an external hard drive again and used Drive Genius 2 to rebuild the disk. Didn't make a difference.

I also removed the Firefox plist file.

Any other suggestions?

Download a new copy of Firefox and move the current version to the trash to do a clean reinstall.

You can find the latest Firefox release in all languages and for all Operating Systems here:

• Firefox 9.0.x: http://www.mozilla.org/en-US/firefox/all.html

if I trash my current firefox will I lose all my bookmarks, add-ons, and preferences? How can I save those?

Your profile data is stored elsewhere in the Firefox Profile Folder, so you won't lose your bookmarks and other personal data if you uninstall and (re)install Firefox.

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

• http://kb.mozillazine.org/Profile_backup

Tried everything. Firefox is still hanging up.

Most recently, I closed Firefox, put it in the trash, put the plist in the trash, emptied the trash, ran the "repair disk permissions" function on Disk Utility, emptied trash, restarted computer as a remote hard drive to run "disk repair" on Disk Utility, and then rebuilt disc via Drive Genius 2. Then I restarted the computer, downloaded Firefox through Safari, and re-installed.

Anything else I can do?