Aha I noticed a lot of plugins inside FF that I was not aware of before. Office, WAG, and Windows foundation + realplayer plugins. I have disabled those now and try again to see..

Edit: I disable all extensions and use only the default theme. Removed all temp files and tried again, but FF keeps crashing. Well I guess I could try re-install it. (even crashed in safe mode).

Reinstalling FF 3.1 fixed it. Guess something was corrupt.