Strange reboot/lockup issue in FFXIFollow

I've been running FFXI on Vista for a few weeks now, and I'll occasionally run into an issue I have yet to explain or find a fix for. Whether it's in full-screen or windowed mode, at several different resolutions, occasionally while running FFXI the system will lock up and a smattering of screen artifacts will appear (no real discoloration, but it looks like a cheese grater was taken to my screen in several spots >.>; ). 7-8 seconds later the sound will start to loop; I can alt-tab, but this kills the display. Shortly thereafter the system will either reboot itself or I'll have to hard reboot. Event Viewer tells me absolutely nothing (The previous system shutdown at xx:xx:xx AM on mm/dd/yyyy was unexpected. O RLY?!). I've got an Intel Core i7, 2.93GHz w/ 6 GB of Corsair Dominator RAM (XMP turned on, so it's "optimized" and running at 1600MHz). BFGTech Geforce GTX 280 OC w/ driver version 186.18 (A downgrade from 190.38, but I seem to run into the reboots less with this version). Doesn't seem to matter what background apps I'm running at the time, I've tried killing everything but antivirus and it will still occur. From eyeballing it, it SEEMS to either occur within the first 10 minutes of playing the game, or not at all. Anyone have any thoughts, stuff I may have overlooked? Thanks.

Screen artifacts are often an indication that your video card is unhappy. Based on the info, I suspect that it might be overheating.

Look for a little free application called SpeedFan. The core temperature of a video card can run significantly hotter than the rest of your box (upwards of 80C when you're pushing it hard). If it's getting any more than that, then try manually adjusting the case fan speed and the fan speed of the video card if it has one (Speedfan does that, hence the name.) If that's still not helping, your video card may be in its early death throes.

Edited, Aug 15th 2009 2:05am by catwho

Going to throw in another vote for the possibility your card is somehow damaged, whether by overheating or not. This sounds almost word-for-word like an issue I had with a number of bad video cards a few months back. If you have another card you can swap in temporarily to troubleshoot, try it out and report back.

There's one possibility I overlooked at first. You are running the Vista version of PlayOnline, aren't you?