I believe this is a result of a microsoft update for windows 7.

http://support.microsoft.com/kb/2670838

It was released yesterday and has caused me the exact same problems.

I managed to fix it by uninstalling the update, restarting the computer and then choosing "start in safe mode". Seems to have fixed the issue.

Hope this helps!

Just to add to my previous post, after starting it in safe mode I was able to run it normally when FF was restarted.

Can you name the update? I hope it will make it work...

The update that caused the crashes (I believe) is the KB2670838 Update (link in my first post). I have heard its caused some issues with other browsers and messaging software also.

Thank you so much! It works now =)

Glad I could help! =]

Last question, when will the update be fixed?