This used to happen "back in the day", but recently it's been reported

Our Novell Clients (4.91 sp4 and sp5) refuse to login to the specified
server. What I mean by that, is the client is configured to login to the
server "", on our tree, in our context. But it authenticates to
another server instead (we have 3 other Netware 6.5 servers on the network,
and it authenticates to them instead).

The reason we use instead of the server name is simply the speed on
login is improved (note - this is a historical thing from much earlier
clients, and may not be such an issue now).

Why is it doing this? The user cannot see any network drives, as the login
script obviously fails. If you try and login again, same problem. Sometimes
a reboot cures it. Most of the time, I end up visiting the machine, manually
trying to browse to \\\sys, and eventually this works, then log in
again seems to work.

Any ideas? It's very strange, and extremely annoying!