[Samba] Trust relationship lost in 2.2.1a repeatedly !

[Yashpal Nagar]

Hi All,
  I have been using samba 2.2.1a as the PDC, as a logon server for about 100 machines.
Till now it has been fine, But for last 2 days all of sudden the trust relationship is lost
from few random machines. Then we again have to reregister with SAMBA domain.
When first time one m/c logins these are the logs.

##############
[2002/10/24 09:58:55, 0] rpc_server/srv_lsa.c:api_lsa_open_policy2(47)
  api_lsa_open_policy2: unable to unmarshall LSA_Q_OPEN_POL2.
[2002/10/24 09:58:55, 0] rpc_server/srv_pipe.c:api_rpcTNP(1215)
  api_rpcTNP: api_ntlsa_rpc: LSA_OPENPOLICY2 failed.
[2002/10/24 09:58:55, 0] rpc_server/srv_lsa.c:api_lsa_open_policy(78)
  api_lsa_open_policy: unable to unmarshall LSA_Q_OPEN_POL.
[2002/10/24 09:58:55, 0] rpc_server/srv_pipe.c:api_rpcTNP(1215)
  api_rpcTNP: api_ntlsa_rpc: LSA_OPENPOLICY failed.
[2002/10/24 10:00:51, 0] smbd/nttrans.c:call_nt_transact_ioctl(1798)
  call_nt_transact_ioctl: Currently not implemented.
##############

Are these logs OK ? or i need to upgrade. What steps should i follow for 
such a network.
Can anyone help please.

Regards,
-Yashoo