I was not successful setting up Windows domain roles in ArcGIS Server 10.0. The Windows groups that ArcGIS Server listed were not the same as the Active Directory groups I wanted to select. We ended up using the option for "users from Windows�?� and �??roles from ArcGIS Server�?�. This setup ended up being the best option since our GIS group does not have permission to add/remove users from a group in active directory, but we can create our own role in ArcGIS Server and add any windows users we want to that group.