I cannot access a directory via samba, even though the user is in a group that
has  rwx access to that directory.  This occurs when the group is not the user's
primary group.  If the directory is chgrp'd to the user's primary group the
problem goes away.

This is using samba 3.0rc3, linux 2.6.0-test5, using a windows XP client.  User
accounts are in active directory and made available to linux via winbind.

In a shared directory:
# mkdir test
# chmod 770 test

# groups mdawson
Domain Admins Domain Users Schema Admins staff business_systems_users IT
Services webadmins
# getent passwd mdawson
mdawson:x:10000:10001::/home/TOTTON/mdawson:/bin/bash
# wbinfo -n "domain users"
S-1-5-21-1123561945-1957994488-839522115-513 2
# wbinfo -Y S-1-5-21-1123561945-1957994488-839522115-513 2
10001
(so domain users is my primary group)

# chgrp "domain admins" test
- access is denied from windows
# chgrp "domain users" test
- access is allowed

Setting the 'force group' parameter on the share makes it so I can use either
the group specified or the primary group, but no other groups.

I can get access to the directory fine from the shell.  I've built samba with
and without acl support and have the same problem.

Let me know if I've missed any important info or if any further tests would be
useful.