G550, games exiting to Windows

[PLAS]

I am running Windows XP and a G550. Some games, MOHAA, Disciples 2, will run fine but will exit to windows with no error message. Any ideas on what could be causing this problem?

System Specs

Athlon 1200 on a ECS K7S5A, G550, SB Audigy. All latest Bios and driver updates.

Thanks

[Tempest]

I'll take a guess. Too aggressive memory timings or PCI/AGP settings? Have you been running any "torture tests" (overnight 3DMark2001 at 1280x1024x32 etc) on your machine?

[PLAS]

No I haven't run any tests like that for a long time. Just reinstalled Windows and since then I have had many 3d problems.

[Tempest]

Okay, if it's a case of "it worked before but now it doesn't" then those memory timings etc probably don't apply. What else could we find... I don't think the same problems that the G400 has with AGP speed apply to the G550. Or do you remember tuning your AGP speed down using some registry hack or tweak utility? If so, download Matrox Tech Support Tweak Utility and lower AGP speed to 2x.
If you say you have installed latest drivers, then you have probably also installed the SiS chipset/AGP drivers for XP?
Well then there's of course ACPI that one can always put the blame on... But I don't think that is what we're looking for either *stumped*