samba - Aug 2002 - samba shares being disconnected on w2k clients

Hello everybody,

I have a strange failure in my samba environment ( samba 2.2.3a ), when
users try to open files on a samba share via the windows explorer. I see the
following messages in the samba log file :

 hcnch049 (10.12.48.103) connect to service homedir as user pa015276
(uid=8065, gid=8048) (pid 19565)
[2002/08/01 08:54:09, 0] smbd/oplock.c:oplock_break(758)
  oplock_break: receive_smb error (Error 0)
  oplock_break failed for file Eigene Dateien/Regio
Chemnitz/B?ro/Fu?ball/Bundesliga 02-03.xls (dev = 40000008, inode = 20998,
file_id = 3413).
[2002/08/01 08:54:09, 0] smbd/oplock.c:oplock_break(843)
  oplock_break: client failure in break - shutting down this smbd.
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service homedir
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service system
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service firma
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service appl
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service groups
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service homedir
[2002/08/01 08:54:09, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service pa015276
[2002/08/01 08:54:09, 1] smbd/reply.c:reply_sesssetup_and_X(988)
  Rejecting user 'pa015276': authentication failed
[2002/08/01 08:54:09, 1] smbd/reply.c:reply_sesssetup_and_X(988)
  Rejecting user 'pa015276': authentication failed
[2002/08/01 08:54:09, 1] smbd/reply.c:reply_sesssetup_and_X(988)
  Rejecting user 'pa015276': authentication failed
  authorise_login: refusing user  with no session setup
[2002/08/01 09:01:10, 0] rpc_server/srv_netlog.c:api_net_sam_logon(206)
  api_net_sam_logon: Failed to marshall NET_R_SAM_LOGON.
[2002/08/01 09:01:10, 0] rpc_server/srv_pipe.c:api_rpcTNP(1200)
  api_rpcTNP: api_netlog_rpc: NET_SAMLOGON failed.
[2002/08/01 09:01:52, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service pa015276 as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:01:58, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service netlogon as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:01:59, 0] smbd/service.c:make_connection(248)
  hcnch049 (10.12.48.103) couldn't find service zaw
[2002/08/01 09:01:59, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service homedir as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:01:59, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service homedir as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:02:00, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service groups as user start40
(uid=951, gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service groups as user start40
(uid=951, gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service firma as user start40 (uid=951,
gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service firma as user start40 (uid=951,
gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service appl as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service appl as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service system as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:02:01, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service system as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:02:02, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service pa015276 as user pa015276
(uid=8065, gid=8048) (pid 21567)
[2002/08/01 09:02:03, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service netlogon
[2002/08/01 09:02:55, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service homedir
[2002/08/01 09:02:55, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service groups
[2002/08/01 09:02:55, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service firma
[2002/08/01 09:02:55, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service appl
[2002/08/01 09:02:55, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service system
[2002/08/01 09:02:55, 1] smbd/service.c:close_cnum(653)
  hcnch049 (10.12.48.103) closed connection to service pa015276
[2002/08/01 09:08:10, 1] smbd/service.c:make_connection(615)
  hcnch049 (10.12.48.103) connect to service homedir as user pa015276
(uid=8065, gid=8048) (pid 21567)

When opening the same file using a windows program ( for example excel ) and
the file open menu in it, there is no problem visible, it?s just the windows
explorer which has the problem.
In the windows explorer, the shares are marked with a red cross, indicating,
that the share is not available at the moment. I use w2k on my clients. 
Has anybody similar experiences, and what?s the problem ? Is there a timeout
parameter available in the samba config ? Or is it a setting on the
w2k-clients ?

I hope  that somebody can help me.

Regards

Chris