Groups within addressbook (on OS X server)

Hello

On my machines with 10.6 & 10.7 clients I transferred all my entries in my local addressbook to the carddav of my server. So now I have my private iCloud, all my entries on all clients in addressbook and ical are up to date.

The problem is, I have no (server)-groups availible on my clients. The only groups listed are the local groups. When I darg & drop entries to this visible group these are copy to local and when you list all, the these are double.

Is their a way to create groups on the server? Is their a workaround?

Regards

Gérard