Big problem.

I think my video card’s semi-fried.
When I run a full-screen DirectX application, such as SSRMAX, the upper-right corner of the screen sorta disappears, like this:

Right below the black section, which seems to fluctuate in size a bit, only background elements show up… and under that, everything’s fine.
It looks like this is only a problem with DirectX apps, as I’ve tried other fullscreen apps like my other beatmania simulators, the most recent StepMania, and World of Warcraft, and they seem to work fine. The tests in dxdiag run smoothly too.
Any smart folks on my friends list have any idea what could be wrong before I pass this on to “the pros” as it were?
BTW, my card’s a GeForce FX 5200, less than a year old. I’m not overclocking it.