[Samba] samba w2k and ActiveDirectory users and groups

[Luis Centeno]

Hello,
 
We've been using samba for the past 3 months. We've a w2k domain (domain1
and domain2.domain1).
Our Linux server FQDN is linux.domain2.domain1
When we run "ls -la" to list the files and permissions, the owner and the
group appear as "DOMAIN1+username" and "DOMAIN1+groupname".
The problem is that from time to time, the system replaces the names with
the number of the user and group( UID and GID ) using the value of "idmap
uid" "idmap gid" from smb.conf.
When this happens, it means (at least for us) the winbindd is not running,
so we call the daemon and KABUM!!!!!!!!!! the names start to appear! 
The problem is that it changes the users and groups mapping, so the file
that had domain1+user1 and domain1+group1, now has domain1+user999 and
domain1+group9999.
how can we try to solve the problem, or at least understand what's happening
here?
thanks a lot
 
Luis Centeno