W2KPro, NT4PDC6a, and Red X’d Net Drives

The workstations are Windows 2000 Pro with SP1, the server is Windows NT 4 SP6a as a PDC, the login script gets the error “System Error 85 has occured. The local device name is already in use” and I have it set up as
NET USE F: \\SERVER\SHARE /YES
but still get the error. The connection is fine and can be browsed but when I save a new file or have a file open and save as a new name I get
“An error ocured while reconnecting f: to \\server\share microsoft windows network: the local device name is already in use, this connection is already in use. This connection has not been restored.”
I’m baffled.
Matt