[Samba] xp problem

[pippo at bellnet.ca]

I would appreciate it if someone can point me in the right direction.
I am having a problem connecting to other computers on my LAN. 
Configuration is this:
1. XP machine, 2 Win2K's, 1 FreeBSD running Samba (current or latest version).
 From XP, I can connect and read/write and print to FBSD but cannot connect 
to Win2k's.
Win2k's cannot connect to XP.
I suspect it has to do with the domain master and the os level settings 
for, when the FBSD machine is off, connections between XP and Win2k are ok.
What do I have to to to be able to connect to Win2k's at the same time as 
the FBSD (Samba)?
I am not running a domain, workgroup only. :))
Thanks in advance,
Pippo