[Samba] tdb file corruption

[Andrew Tranquada]

Hello all,
We are using samba/winbind for authenticating users using Active Directory
(2k8) as our  "backend". We are using the rid idmap backend. Everything is
working perfectly, except on a few boxes I have noticed that users we could
look up before, return just the id (not the name),or "user not found".
Stopping samba/winbind, removing the idmap_cache.tdb file then starting
samba/winbind has fixed this problem every time. It has not happened
multiple times on the same box, but has happened a few times on different
servers.
We are running RHEL 5.3/5.4 using their version of samba,
3.0.33-3.15.el5_4.1 (which is the latest RHEL provides) . From the
documentation I notice that it does say that the tdb files can get
corrupted, however I was wondering if the newer versions of samba suffer
from less tdb file corruption, or if there is something I can do to either
prevent/lessen the chances of the tdb file getting corrupted.
Also, is there a specific event that happens that causes it to get
corrupted, or are there a vast variety of reasons?

Thank you.

smb.conf:

netbios name = <redacted>
workgroup = <redacted>
security = ads
realm = <redacted>
        use kerberos keytab = true
        idmap backend = rid
        idmap uid = 4000-100000000
        idmap gid = 4000-100000000
        winbind enum users = yes
        winbind enum groups = yes
        auth methods = winbind
        template shell = /bin/bash
        template homedir = /afs/<redacted>/home/%U
        winbind normalize names = yes
        winbind use default domain = yes
        allow trusted domains = no
        winbind cache time = 3600

-- 
Andrew Tranquada
Sent from Blacksburg, VA, United States