NIC problem 8139too & 3c2000

[yavorsky gaetan]

Not only a FC1 problem, same with RH9.
SAMBA 2.2.6 / 2.2.7 / 3.0 servers running RH9 / FC1 / MDK91.
Window$ clients running 2000Pro, XP Home, XP PRO.
Clients with realtek chips ( Linux driver 8139too ) have problems 
working with SMB/Linux
with giga NICs 3c940 ( Linux driver 3c2000 ).
Looking in Samba logs, I can see many oplocks problems, and many 
failures reported by the client .
( timeout, loose smb network, many smbd process started for tthe same 
client, general window$ failure, ... )
Same clients work fine with SMB/linux serveur with 100 Mbps NIC ( 
realtek or 3c905 )

1) 3c2000 problem ?
But if I change the NIC on the client ( from realtek to 3Com for example 
) all is OK whatever the server NIC is.

2) 8139too problem ?
But if I change the NIC on the server ( from 3Com 1000 Gpbs to any 
100Mbps ) all is OK whatever the client NIC is.
If I don't change any of the NICS, but cold start the (dual boot Linux 
FC1/Win2000) server with Win2000, all is OK.

3) Network problem ?
IP network seems to work correctly ( but samba of course ), ifconfig on 
the server side shows no error, no collision, ...
IP www, ftp, telnet, ssh, are OK.
All I can see while looking a "strace -p smbd_process", is that the 
server is sending a packet to the client, and is blocked !

4) Samba problem ?
I tried many Samba different releases, and all seems to be OK ( tried to 
disable oplocks ->same result )

I don't know what to check anymore.
Any advise ?
Thanks.
Gaetan.