It's happened to me before and it's so annoying
Visual Studio just crashes and crashes and crashes - and it's not so easy to work out what to do...
First try the log file:http://blogs.msdn.com/saraford/archive/2008/11/27/did-you-know-there-s-a-way-to-have-visual-studio-log-its-activity-for-troubleshooting-366.aspx
Then try the reset commands... basically type /? on the command line and you get options like /resetskippkgs and /resetaddin and /resetsettings
I'll try anything - I just want to get on with work!