PDC, security = domain

[Steve Lee]

I have a PDC setup, all works great
in windows ( so far ), however when i try
to setup the other unix machine to use
the PDC with the security = domain, i can't
get into the machine, windows always prompts
me for a username password.

What are some of the settings for the other
unix machine running samba to authenticate
from the PDC with its setting at
security = domain,  

please advise