TIGER K8w Dual opteron crash

[Manuel Capinha <mcapinha@gmail.com>]

Hi all.

I'm running the gcc-3.4 distro, on a dual opteron motherboard.
Since Monday (Jan 3) this machine has been crashing randomly and I
can't find a pattern to why this happens. The 3 times it has crashed,
it was always running a X session so I can't even get to the console
and look at the stack trace.
When the machine crashes it just freezes: all input is ignored. Mouse,
keyboard, networking nothing works... the machine is just dead in the
water :/

This happened for the first time a short while after doing an apt-get
dist-upgrade.

So, if no one else is experiencing this behaviour, maybe someone could
give me some pointers on where to start looking ? Especially, if
there's any way to access the console or force the stack trace to be
written to the harddrive maybe ?

The machine is using a TIGER K8w motherboard, 2 Opteron CPUs, 1Gb of
RAM on 2 DDR sticks and 2 Seagate SATA harddrives running on RAID 1.

Any help is appreciated, off course.
Thanks in advance,
Manuel Capinha