8.2 and 9.0 on same lan

We have an all 8.2 lan (NIS via NFS) with one 9.0 client. Under kde the 9.0 box gives errors 'xxx cannot be reached by dcop' or 'Klauncher cannot launch xxx' OWTTE after anyone on a 8.2 client has looged out whilst using the same account. (they are students in the same class using the same login). Can anyone help me here? Thanks, Steve.