samba - Nov 2004 - Adding domain user as local administrator

Hi,

I've noticed that if I add a domain user as a local administrator on the 
client system (WinXP logging into Samba 3.0.7 domain) they seem to have less 
local rights than a local user as a local administrator.  Is this a Windows 
thing or is this something to do with Samba?

Thanks,
Misty