setup: PC ----- SWITCH ---- SERVER

PC runs Debian/Windows XP, Server RedHat 9; when XP --- RH9 everything is OK, but when Debian ----- RH9, we have a problem.

NIC used in PC: Nergear FA311 (D2), (dp83816 chipset)

Each working driver module works (or doesn't in this case) the same way:
My local TCP/IP stack works, I can ping localhost (127.0.0.1) and my own IP (10.0.1.1); I can't ping server (10.0.1.2) or any other device on the network, and they can't ping me.

I can see significant increase in TX "dropped" when trying to ping, while RX never "receives" anything, even though the switch shows that the traffic is physically there.

I've tried:
different drivers (original, older but for my kernel version, and some I found somewhere)
different network settings / startups
flushing and deleting all iptables' chains on both stations (CLI-SRV)
adding static route
unsuccessfully adding arp entry
setting manually speeds and mtus on both sides

And that is pretty much all I have.... Thanks for your time and help.
Tomas

I have found the "natsemi.c" driver and compiled it (the source of Makefile is a must), then copied to /lib/modules/2.4.20/kernel/drivers/net/ ... Then I stopped networking (/etc/init.d/networking stop), put eth0 down (ifconfig eth0 down) and ran modconf. Then removed the FA311.o and added the new listed there... Then brought network up to life (/etc/init.d/networking start) and looked at eth0, it was configured so I didn't have to do anything... And ping my server worked. Then I just restarted and saw that even after restart everything works...

Tomas