There is a bug/issue that I reported years ago for VS 2005 and was not even acknowledged as a bug but “by design”. VS 2010 (Beta 2) still exhibits it so I keep pushing to get if fixed (the original bug report was lost, I think it died when MSDN Product Feedback became Microsoft Connect):
VS 2010 Beta2: importing settings destroys commandbars created by add-ins
The problem is that Visual Studio thinks that all the commandbars of the IDE belong to it, ignoring the fact that some commandbars belong to add-ins and it should ignore them when importing settings, rather than resetting them or destroying them…
To complicate things, when the add-in is unloaded at some point later (by the user or closing VS), it doesn’t have a direct way to know if its commandbars have been destroyed by Visual Studio, so it tries to delete them and it gets a ObjectDisposedException….