samba - Oct 2002 - Group write permissions denied when using username map

Samba 2.2.5, security = domain, using winbind and a username map for users
with a corresponding UNIX account. 

Interesting thing:  once I got my username map working and the NT users are
getting their correct UNIX UID when they access the shared area from the PC,
they are no longer being identified as members of the "domain users"
NT
group,  which means they can write to the shared directory from the UNIX
side (world writable by anyone with access to the UNIX machine),  but they
can't write to it from the PC side (write list = @"WALNETNT_Domain
Users")
of which they are members... 

Any ideas why this is?  

	Thanks,

		Karen Wieprecht