I didn't see that anyone else posted about this...
I'm running Steam via Crossover 13.0.1, on Mint 16 (64 bit). Most of my games seem to run just fine. However, every time I exit games (run full screen) the mouse is trapped in a roughly 1024x768 rectangle in the upper left section of my screen. My laptop is 1600 x 900, and the entire resolution is correct, but you can see a section of the wallpaper in that area, while the remainder of the screen shows the Steam window. I've tried a few things but the only solution that works so far is to log out of Mint completely. I'm running Cinnamon, but it also happens with MATE. I can bring up the main mintMenu with the "windows/Tux" key, but the cursor doesn't leave that section no matter what, and I can't select anything on the menu. I have to Ctrl-Alt-Backspace to log out.
Torchlight is the only game I have which doesn't seem to have this problem at all.
Does this happen to anyone else? I've tried using PlayonLinux, but Steam crashes so I'm missing something when I run it that way. I don't know whether I need to configure something in Crossover, or something about my desktop. If I can figure out how to avoid this, I'll be ready to ditch Windows completely.