[Samba] Strange SAMBA4 situation

[Cezar BALANESCU]

Hello,

I am facing a strange situation:

I have downloaded the sources with git, configure and compiled (Samba
Version 4.1.0pre1-GIT-76fa5ee) just like in the HowTo doc, here:
https://wiki.samba.org/index.php/Samba4/HOWTO
All the tests were ok. I am using internal DNS of Samba4.
I have successfully added one XP machine to the domain controlled by
samba server. On this XP system I have successfully installed Windows
Server 2003 Administration Tools Pack and I am able to "see" the active
directory structure in the management consoles.
I have added the scripts to autostart samba after rebooting (using
upstart services in ubuntu).
Now, after I am restarting the server machine, samba4 starts ok, but
when I try to access the active directory structure I am getting a
message informing that the Naming information cannot be located because:
The Local Security Authority cannot be contacted.

In the Event Log of XP client system I have two warning messages issued
by LSASRV.DLL:
1) The Security System detected an attempted downgrade attack for server
ldap/samdom.local.  The failure code from authentication protocol
Kerberos was "There are currently no logon servers available to service
the logon request
and the second,
2)The Security System could not establish a secured connection with the
server ldap/samdom.local.  No authentication protocol was available.

In log.samba file I have: [2012/11/13 11:32:58,  2]
../source4/auth/ntlm/auth.c:420(auth_check_password_recv)
  auth_check_password_recv: NO_METHOD authentication for user
[(null)\(null)] FAILED with error NT_STATUS_NO_SUCH_USER

If I restart Samba4 service, I can access the active directory structure
from the XP client system.