Hey Bartman1967,

Have you tried starting Firefox in Safe Mode? Hold down "shift" while Firefox is starting up. If the crash doesn't happen in Safe Mode, you should read Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.

There is also a lot of useful stuff in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) Knowledge Base article. If you've recently upgraded, you might want to check out this article as well.

Hopefully this helps!

Did you update Roboform recently?

Yes, so I went back to the previous version and it seems OK at the moment, I have also emailed Roboform, but yet to get a reasonable response from them.

So I believe that this mystery is solved, until Roboform fix their problem.