Recently I had a situation with Visual Studio 2010 where menu items where duplicated like 3-4 times. Looks like some configuration file was corrupted. I have tried to restore current settings and setup new settings but none worked out.
To resolve this I ran the following from command line
devenv.exe /safemode /setup
Once this ran, I restarted Visual Studio I could able to see Visual studio with default factory settings.
PS: If you have any personal settings done before you have to redo those settings again.