Can't Map Share via Compute Name

[Backhand]

Getting "...duplicate name exists on the network..." error.

Desktop XP Pro name UPSTAIRS, static IP 192.168.1.100. Notebook is
named NOTEBOOK and static 192.168.1.103.

HOSTS and LMHOSTS have entry pointing NOTEBOOK to 192.168.1.103.

WINS is set to enable NETBIOS.

I can ping NOTEBOOK by name, it is resolved and pings.

net view by \\computername gives same error.

I try to map a share by name and I get the above mentioned message.
Mapping by IP is no problem.

When this first occurred to me, several months ago, I found a
reference about setting WINS to enable NETBIOS. The first time I did
this it resolved the issue. The setting has not changed and the issue
is back.

Ideas?

 

[Backhand]

More info:

NOTEBOOK is Win2k.

Other Win2k boxes have no problems with mapping their shares via name.
NOTEBOOK is on a domain although it is not connected while sitting
here. It had worked in the past in this config, just not now.