Hi, I'm the one who have the problem with the desktop background.
I have two monitors attached to my graphic card, both 1920x1080. Maybe this problem is caused by nView, because I use it so I can have two different wallpapers (you can see part of the wallpaper from the other monitor to the right of the screenshot). Without nView managing my wallpapers, it seems to work fine.
The problem shows up randomly when I use Alt-Tab. Sometimes it is fixed after I exit the game, and other times the background is still messed up after I exited the game.
The smaller image on the screenshot (in the first post) has the same resolution as when I ran the game in fullscreen mode. I don't have any problems when I run in windowed mode. I have msn and firefox running, and no custom taskbars or other tweaks.