Access Denied when trying to Join Domain

Hi --

I recently reloaded my server with OpenSuSE 13.1. The network had worked fine, but now if I try to join a workstation to the Samba Domain I get the message, "Access Denied." I suspect that there's a switch somewhere in Samba or Netlogon or some other place that will enable a workstation to join the domain, but I can't find it.

The server reload was relatively simple; LAMP server, file server, no games or multimedia. In the previous incarnation (OpenSuSE 12) the workstations had no problem joining the domain. Since the only change was the server, I think the problem is there.

Can somebody advise?

Thank you.

cheers,
pete