samba - Dec 2003 - "Specified network name is no longer available" error message

I'm having issues when trying to connect to a Samba 2.2.5 server on a Unix
box.  I am able to successfully run smbclient locally on the machine and also
from another Samba server and I'm able to browse the shared directories
using smbclient.  But when I try using any Win2k SP4 client, by either browsing
with My Network Places, or just by trying to map a drive, I get the following
error message:

The specified network name is no longer available.

Any ideas on how I can troubleshoot this?

Thanks.

-----------------------
Alan Olegario
http://www.fxall.com
alan.olegario@fxall.com
(P) 646-268-9988
(F) 646-268-9996
(C) 732-803-2530