samba - Jun 2003 - group mapping problem (winbind 3.0.0beta1-1)

After upgrading from winbind 2.999+3.0.alpha to 3.0.0beta1-1 I have a
problem with group mapping, gids are not expanded into group names:

# touch /tmp/x
# chown nobody:"Domain Users" /tmp/x
# ls -l /tmp/x
-rw-r--r--    1 nobody   10000           0 2003-06-13 16:46 /tmp/x
# wbinfo -G 10000
S-1-5-21-159198177-51124254-1951487848-513
# wbinfo -Y S-1-5-21-159198177-51124254-1951487848-513
10000
# net groupmap list ntgroup="Domain Users"
[2003/06/13 16:49:17, 0] passdb/pdb_smbpasswd.c:pdb_init_smbpasswd(1562)
  idmap uid range defined, non unix accounts enabled
  Domain Users (S-1-5-21-941073734-1356708048-2792949991-513) -> -1

What does '-> -1' mean?

# getent group|grep "Domain Users"|cut -d: -f-3
Domain Users:x:10000

But as shown above 'ls -l /tmp/x' does not expand gid 10000 into 
"Domain Users".

I am using winbind and samba from Debian/sid.

-- 
cheers,
Marco De Benedetto