Psycho-Shimmy

Good evening! I have no idea if I made it in the right section. If not -> Sorry about it. Anyways, I got a Enemy Territory server and I was checking a player. I made a Punkbuster-screenshot to check if he's clean. But when I made it, this appeared: Any idea? I asked him about his GFX-card, because sometimes a screenshot is gray (But you can see something. This one you can't.). And he got a 7900GT. I don't got more information. Thanks for helping me. :)