I think this same problem is causing SSMS 2012 to crash on exit as well. This is the error I see in the event viewer:
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: exception code c0020001, exception address 76CD4B32
I think it might be related to this issue: http://connect.microsoft.com/VisualStud ... ocess-exit