I had all kinds of problems when I bought a new y00tz. It would randomly delete the wrong forum posts and stuff. I think most of the kinks are worked out now, though.
On a serious note, you might want to try disabling JPEG screenshots to see if it's a problem with getting the screen data or compressing the files. You might have to download a program to view TGA files, though. Also, you can set xfire up to take screenshots, too. The default key is like scroll lock + Q, but you can set it to F12 or something else.