Using Windows AD Groups

Hello all.
Firstly, apologies for the vague topic/subject!
The scenario is I have a Windows Server 2003 Domain Controller which runs ADUC. I have created some security groups which I would like to apply to my network shares.

The problem is, the network shares are on Open Suse. Now although the servers are part of the domain, when trying to configure the shares using Samba, do not allow me to select the Active Directory groups.

Please does anyone have a solution which will allow me to use ADUC security groups?

The Suse machines authenticate against the active directory OK.