Gigabyte GA-K8NF-9 BSOD IRQ NOT LESS EQUAL

Hi Guys,

Hope someone can make some suggestions here.

Got a two year old PC here running winXP SP2. Been running fine for a
while then one day whenever you go to turn it off or reset via
software you get a BSOD at the very last second before you would
expect the power off (after you go to the blue screen where windows
says shutting down).

Now I tested the ram all night with memtest. No problem.

I tried it in Safe mode - same problem.

I turned off everything in msconfig - same problem.

Tried a new Power Supply - same problem.

Ran Prime95 all night - no errors.

I am thinking now its the mobo, but since this mobo is no longer
available I would like to be sure before I buy a similar one, that the
mobo will fix it. Anyone have any more ideas?

The exact error is the IRQ NOT LESS OR EQUAL with the first parameter
being 0x0000000A.

Its a AMD 64bit chip - socket 939.

Cheers

-Al