In testing, the user on a db i\'ve used was a big jefe. In production, he only has Execute.
When I called,
Membership.DeleteUser(user)
If the error (or similar) still persists after granting the ASP user SELECT on the vw_aspnet_MembershipUsers, you may want to grant SELECT for some of the other vw_aspnet_???? views too. Especially "profile" and "UsersInRoles". Otherwise - for some reasons, the DeleteUser SP gets an empty result when SELECTING from those views and refuses to delete existing entries from them first.