FireFox won't open.

[tekmate]

I am trying to help someone get Firefox working it bounces in the dock once and then disappears. It is profile specific because if I login it works fine. Safari still works and so does an old copy of IE. I cleared the caches which didn't help so I deleted the mozilla folders in the user library didn't help so I deleted that one and the one in system library also didn't help. I could not locate a plist so I tried Camino which was also on the machine again it works for me but not him. So I uninstalled Firefox and Camino and tried reinstalling Firefox it won't let me reinstall as him says he doesn't have permissions yet he is an admin on the box. So I tried repairing permissions no luck he still can't install Firefox or use it if I install it under another account. I am at a loss other than deleting his profile but he has a ton of data and custom settings and I don't want to have to try and recreate everything. Any help would be greatly appreciated.