[If you receive the mail twice - sorry. I forgot to attach the actual patch]
Hi,

Attached is a patch that modifies the tx interrupt handling of the 
nForce nic. It's part of the attempts to figure out what causes the nic 
hangs (see bug 4552).
The change is experimental: It affects all nForce versions. I've tested 
it on my nForce 250-Gb.

Please test it. And especially: If you experince a nic hang, please send 
me the debug output. That's the block starting with

<<
NETDEV WATCHDOG: eth1: transmit timed out
eth1: Got tx_timeout. irq: 00000000
eth1: Ring at  ...
<<

Thanks,
    Manfred