proble with "modify_trust_password"

[JANTZEN, Eric]

 Hello,

I have a little problem:
on our network, the PDC logge some event
Event ID: 2006, Source: Svr, The server received an incorrectly formatted
request from \\LABOS

and when I search on the samba log, I see this:

---begin---
p11060 (10.11.161.18) connect to service labo_str as user girl_str
(uid=5012, gid=6006) (pid 13526)
[1999/10/27 15:22:21, 0] rpc_client/cli_pipe.c:rpc_api_pipe(297)
  cli_pipe: return critical error. Error was ERRSRV - ERRerror (Non-specific
error code.)
[1999/10/27 15:22:21, 0] rpc_client/cli_pipe.c:cli_nt_session_open(1080)
  cli_nt_session_open: rpc bind failed. Error was ERRSRV - ERRerror
(Non-specific error code.)
[1999/10/27 15:22:21, 0]
rpc_client/cli_netlogon.c:modify_trust_password(569)
  modify_trust_password: unable to open the domain client session to machine
CRITD001. Error was : code 0.
[1999/10/27 15:22:21, 0] rpc_client/cli_pipe.c:rpc_api_pipe(297)
  cli_pipe: return critical error. Error was ERRSRV - ERRerror (Non-specific
error code.)
[1999/10/27 15:22:21, 0] rpc_client/cli_pipe.c:cli_nt_session_open(1080)
  cli_nt_session_open: rpc bind failed. Error was ERRSRV - ERRerror
(Non-specific error code.)
[1999/10/27 15:22:21, 0]
rpc_client/cli_netlogon.c:modify_trust_password(569)
  modify_trust_password: unable to open the domain client session to machine
D_FEBUS2. Error was : code 0.
[1999/10/27 15:22:22, 0] rpc_client/cli_pipe.c:rpc_api_pipe(297)
  cli_pipe: return critical error. Error was ERRSRV - ERRerror (Non-specific
error code.)
[1999/10/27 15:22:22, 0] rpc_client/cli_pipe.c:cli_nt_session_open(1080)
  cli_nt_session_open: rpc bind failed. Error was ERRSRV - ERRerror
(Non-specific error code.)
[1999/10/27 15:22:22, 0]
rpc_client/cli_netlogon.c:modify_trust_password(569)
  modify_trust_password: unable to open the domain client session to machine
D_FEBUS1. Error was : code 0.
---end---

Any idea??

Thank's

Eric JANTZEN