samba - Sep 2003 - get_domain_user_groups: You should fix it, NT doesn't like that

Running Samba 3.0 on Linux 2.4.21 with acl patch.  The NT box is an NT 4
SP 6 Server.  The Samba is set up as a PDC.

I have a file F:\c.txt, which is owned by user usera with Special Access
(of Take Ownership, only) given to user userb.  If I log in as userb and
try to do take ownership on that file we get the error "Access Denied"
from the GUI and immediately in the log, I see:

  [2003/09/30 11:12:11, 0] rpc_server/srv_util.c:get_domain_user_groups(371)
    get_domain_user_groups: primary gid of user [usera] is not a Domain group !
    get_domain_user_groups: You should fix it, NT doesn't like that

usera's primary group is users:

  usera:x:1001:100::/dev/null:/bin/false

The group `users' is in /etc/group:

  users::100:

which is groupmap'd to Domain Users:

  Domain Users (S-1-5-21-938323123-1062378614-4074567964-513) -> users

Which makes the entry in the log file seem nonsensical.

After this error occurs in the log (/var/log/samba/log.ntbox), I try
logging in as usera and I received the following error from the GUI:

  "The local policy of this system does not permit you to log on
  interactively."

If I restart Samba the usera can log in again fine.

Any thoughts on what I might be doing wrong?

Thanks,

Erik.