Hard lockups

[stan]

I've got an Athalon 1.2G machine that has been stable as a rock fo over a
year now. 

That is, untill I change from ThinNet network cableing to 100BaseT full
duplex networking. Now it locks up solid (jeyboard does nothing, can't
telnet in, and screen is frozen) about once a day. I've changed NIC's (even
changing brands) and this does not cure the problem. I've cvsup'd (as
recently as last night) and rebuilt te system. I've run memory tests
(metmtest85), I've run disk tests (Hiticha's drive test program). I've even
set eh motherboard to fail safe defaults. All to no avail.

This lock _appears_ to be related to periods of high network activity.

Can anyone provide any sugestions as to where to go next in my effor to get
this machine back to it's expected stabilty?

Any sugestiosn appreciated.

-- 
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
						-- Benjamin Franklin