samba - Mar 2007 - NET_SAMLOGON failed

I'm looking at /var/log/messages and see SAMBA messages error

Mar 13 10:39:43 server smbd[1289]: [2007/03/13 10:39:43, 0]
rpc_server/srv_netlog.c:api_net_sam_logon(206)
Mar 13 10:39:43 server smbd[1289]:   api_net_sam_logon: Failed to marshall
NET_R_SAM_LOGON.
Mar 13 10:39:43 server smbd[1289]: [2007/03/13 10:39:43, 0]
rpc_server/srv_pipe.c:api_rpcTNP(1200)
Mar 13 10:39:43 server smbd[1289]:   api_rpcTNP: api_netlog_rpc: NET_SAMLOGON
failed.

What could it be? I looked at history of lists.samba.org and didn't find the
solution...

Regards.