Kitchen Soap

when you see this:
(loaded box, lots of network, 2.6.9.x kernel, etc.)
Dec 21 04:05:58 hostname kernel: ————[ cut here ]————
Dec 21 04:05:58 hostname kernel: kernel BUG at net/ipv4/tcp_output.c:927!
Dec 21 04:05:58 hostname kernel: invalid operand: 0000 [#1]
Dec 21 04:05:58 hostname kernel: SMP

do this:

Add to sysctl.conf:
net.ipv4.tcp_retrans_collapse = 0