I have a Leadtek / Nvidia PX 8600 GTS dual DVI card in an Acer Aspire T180 box which has an AMD Athlon-64 X2 4000+. I can give North/South bridge details if anyone thinks they need it.
Basically the system is fine, stable, no crashes - except when I run a 3D application like a game (usually RtCW:ET but any 3D game seems to do it, including the test application, under Vista, that came with the card).
Under Vista (32-bit Home Edition) and Linux (Ubuntu 64-bit 7.10, 8.04 and 8.10alpha) the behaviour is the same which strongly suggests that the problem is the hardware. But I can't work out why when it crashes and then reboots (forced or not), why after reboot it works fine and never crashes another time.
It doesn't matter if it's done immediately I start using the comp or after having it on for an hour or even a whole day, still the same - which suggests it's not a simple heating problem.
I've gone through several driver upgrades on both sides, now using the nvidia-glx-177 drivers under Ubuntu 8.10 alpha6 (and whatever the latest stable are on Vista).
I don't get anything extraordinary in my /var/log/xorg.0.log file but Vista sometimes gives a blue screen with BCCode 116 ("general video fault" from what I can tell). The appearance of the screen is always similar, it's the last screen with lots of short horizontal lines and the last sound clip will loop until reboot. In Linux I can do Alt-Sysrq-R -E -I to kill the X-session, or I can Ctrl-Alt-F1 and see the console, but it's messed up in same way that the X session is and isn't always responsive except to the Alt-Sysrq calls.
Like I said, on reboot it always works flawlessly and has never crashed a second time ... could the BIOS be changing the clocking or something?