samba - Nov 2009 - AllowUsers AllowGroups + WinBind

Hello, 

I was hoping that someone could shed some light on this issue we are 
having. 

I'm trying to use AD groups to allow SSH access into the Linux boxes but 
It doesn't seem to work. 

We have: 

AllowGroups unix_admins 
AllowUsers joe at server1.domain.com 

And doesn't work. If I remove the first one it works great joe can login 
into the box from server1. 

the end objective that I want is to restrict access to groups. let's say I 
want the group unix_admins to be able to log in into the box but only joe 
from server1.domain.com 

Any help will be appreciated. 

Thank you. 

Roberto Bouza.