I just added a new server to our tree. Most users can so far can map to
the server fine. But a few PCs are having issues, those PCs get an error
"LOGIN-LGNWNT32.DLL-890:The specified server is unknown".

Not every PC that has client 4.91sp2 is getting the error.

The old servers are Netware 6.5 sp3, the new server is Netware 6.5 sp6.
Updating the client seems to help, but one server that is getting the
issue is our Citrix server, and I do not want to take it down.

The PCs that can not map to the server can ping the server. My network is
small, 3 servers and everyone is in the same partition.

Any ideas on why some PCs would not map a drive to the new server?