I am running the following WMI query from a domain account which is in the local Administrators group on my server:
select * from Win32_GroupUser where GroupComponent = "Win32_Group.Domain='WIN2000SERVER1',Name='Administrators'"
and it returns most of the members of the group. However, it doesn't return domain groups which are "Domain Local" groups. It returns "Global" groups correctly and all users and local groups.