Novell - preferred server not working

[SpiderD]

We have remote users who dial in via DUN1.3 (98se2 on various Compaq notebooks) to a mixed NT/Novell network with NDS. Despite having "preferred server" set in the client settings, and the same server hard-coded into the login scripts, we get a connection to one of our other subsidiary Novell servers. No useful drives are mapped, and you can't map them manually. This doesn't seem to be platform-related, and doesn't affect all users. Usually it goes away after a week or two, only to start again later. I've tried using net.cfg with both Netware Reqester and Netware DOS Requester (clutching at straws here) with no change. The user is logged on to NT OK. I think there's some kind of time-out running, where the preferred server doesn't respond within a given time, but our Novell whiz thinks not. Any thoughts?