Active Directory group permissions not being applied to user [duplicate]

Question

I have an odd situation. An Active Directory group was recently created for the sole purpose of being a securable in SQL Server. I created a login based on the AD group, a user based on the login, and granted permissions to the user. All pretty standard stuff. When I impersonate one of the group members (using execute as login='domain\username'), I'm able to perform the granted action. However, when the user himself tries it, he gets "permission denied". I'm at a loss to explain the behavior and subsequently fix it.

Answer 1

Is your service account an AD user? It would need to be to evaluate group memberships, for example. (If you're logged in as an AD user, SQL can evaluate those permissions.)

Microsoft recommends using a domain user for service accounts.
http://msdn.microsoft.com/en-us/library/ms143504.aspx

Answer 2

Depending on the Windows version and how the user is attempting to run their query, it may be UAC. I've successfully used this link to solve similar issues for multiple clients: http://www.sqldbops.com/2010/05/token-based-server-access-validation.html