Blue screen (not BSOD, however)

Finsihed my system recently. Here you go:

DFI LANPARTY UT nf3 250gb
AMD 64 3000+
ATI Radeon 9800 Pro
1gb Corsair ValueRAM
Maxtor 200gb
Samsung 915-N LCd (not sure if that matters)

Here's the problem. I recently bought SimCity 4 and in the middle of playing was plagued by a black flash and then a blue screen. It wasn't a BSOD (there was no message; just a blank, blue screen.) After this happened several times I uninstalled SC4 and am returning it.

So then I downloaded the BF2 demo and it ran great, until in the middle of playing, the same thing happened. This time, however, I noticed there was a decrease in frame rate and then it crashed.

>I was forced to restart my system every time this happened.
>I am not cooling my card except for 3 80mil case fans and one 120mil jet fan.
>This does not happen with any other games (ie. While playing HL2 and CS: Source for hours on end.)
>Kinda funny the problem only lies with EA Games, isn't it?
>SimCity 4 was updated, however, BF2 was not.
>I ran both games at highest resolution supported by the games (SC4 1280x1024, BF2 1280x960)

So, is my card overheating? Are there driver problems (I have the most recent)? What's going on?