In the following circumstances:- Windows Vista with UAC activated- VS 2008 SP1 runs as standard user even if you are an administrator (the default, you would have to use the "Run As Administrator" context menu otherwise)- COM-based add-in (not .AddIn XML-based add-in)- Add-in registered for all users (HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Addins)- When the standard user tries to load such add-in not marked to load on startup through the Add-In Manager, it doesn't load and if you go back to the Add-In Manager the checkbox is still unchecked.- When the user tries to unload such add-in marked to load on startup through the Add-In Manager, it doesn't unload and if you go back to the Add-In Manager the checkbox is still checked.That doesn't happen for .AddIn XML-based add-ins registered for all users, only for COM-based add-ins registered for all users.
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