Some more info on this issue:
Today I was running 2 instances of VS2008 - different VWG projects. One is small one, the other large. Both use a 'form' as a user control. Neither was running - both in design mode. One had been run several times, the other simply opened in design mode.
At the time, neither project had any forms opened in design mode as I recall - but in the larger project I had opened and closed the designer while removing some redundant controls - these were deleted over several stages.
I left the PC and had lunch, when I returned both instances of VS crashed with this bug, at almost the same time - by the time I dismissed all the messages on the first instance, the second (had) crashed.
On the second instance I allowed the debugger to run and captured some info on the error. I have sent this to the support email address "Cannot access disposed object: DesignerFrame - 20120224". The unhandled exception was in devenv.exe, but clearly some common event caused both instances to fail at the same time.
- I had just used Tortoise SVN to update the source control repository for the larger project.
- The screen saver had triggered - but I used to get the problem before when I didn't use a screensaver.
Hope this is helpful