[Samba] Win 7 - Rejecting auth request from client

[Phil Anderson]

Hi,

I have an odd issue where I'm getting auth request failure errors for all
my Windows 7 machines.  The strange thing is that everything appears to be
functioning perfectly.  I can add machines to the domain, log in as domain
users, browse domain shares, and the machines regularly change their trust
password.  So functionally, everything is fine.... it's only the log
message which is concerning me:
rpc_server/netlogon/srv_netlog_nt.c:976(_netr_ServerAuthenticate3)
  _netr_ServerAuthenticate3: netlogon_creds_server_check failed. Rejecting
auth request from client MACHINE machine account MACHINE$

I'm using an ldap backend, and the underlying ldap data looks fine.  I can
see the trust passwords changing regularly.  This logged errors only occur
on Win 7 machines (XP is fine) and I have applied the documented changes to
the registry.

Can anyone suggest any additional logging so I can track down the cause of
these auth rejections?  I tried increasing the log level on a few other
subsystems, but it didn't suggest anything obvious.  Or should I just
ignore these?

I'm running Samba 3.6.9, but the same problem was occurring previously on
3.5.

Thanks,
Phil