G400 + Win2k = Hard Reboot

[Poseidon]

Here's my system.

Soyo K7AIA MB
Classic Athlon 700
256 MB Memory
'Vanilla' G400 32MB AGP
300 Watt PS
SB Ensoniq
DLink NIC
ATI TV Wonder
Aopen ISA Hardware 56K Modem
20GB Fujitsu Hard Drive

And I've installed the following, in this order:

Windows 2000
Windows 2000 sp2
Matrox G400 Drivers 5.52
Directx 8
AMD Athlon Registry Fix
AMD AGP/IDE Drivers
Diasbled AGP Texture Acceleration

Now, I haven't yet (but have previously)
Scaled down to 1x AGP

And I have already:
Installed latest Bios Upgrade for G400
Soyo has no new bios upgrades.

This time, I tried ACPI (to no avail) and the G400, SB Ensoniq, and DLink NIC are on IRQ 9. Before, I had it on a seperate IRQ, but that didn't solve my problem.

Here's my problem. In the following games (That I can think of)

ST Dominion Wars
Mechwarrior 4
Sacrifice

And others (I'm at work - I don't remember some of the others), they all hard reboot. I read somewhere in the forum about Win2k automagically rebooting on a crash. Sure enough, when I turned this off, it simply blue screens me with a VDX error.

Here are some other things I've noticed:

When it reboots/crashes, it almost exclusively occurs when something happens in the game. IE - something dies/starts shooting/blows up, etc. It also makes a sound from the game, ie. crashes seem to coincide when a sound is triggered. Not exclusively (I was able to play for an hour last night with no crashes!!)

The card isn't running all that hot. I've tried taking the side of the case off, and blowing air onto it, but it doesn't help.

Anyone have any ideas?

Cheers