Not sure if this has anything to do with it, but make sure you are in the User Group 'VS Developers' along with being a pc admin. the Local Administrator Account is added to this group when VS.Net is installed, so that could be why you are getting the error with your "admin" account and not with the Local Administrator Account...
Right Click My Computer then Click Manage and goto Local Users and Groups -> Groups -> VS Developers and add yourself. Also Add yourself to Debugging Users if that doesn't solve the issue.
-Bob