I have a dual screen setup which I've configured by running this command at startup:
xrandr --output VGA-0 --auto --right-of DVI-0
I'm running OpenSuse 11.4 with dwm as my window manager. I can post the output of any command or dump any file if you think it will help.
The problem happens when I try and run a fullscreen game. My right screen goes black and loses the signal. On the other screen, my resolution goes down and I see a magnified version of the upper left corner of my desktop (the dwm tag bar). I can hear the game audio but I can't see anything other than what I described above.
Another important thing is when this happens I need to reboot (or at least restart X) because I get no input and can't close anything.
EDIT 1
02:00.0 VGA compatible controller: ATI Technologies Inc Juniper [Radeon HD 5750 Series]
I'm not sure how I can find what driver I'm using, but I expect it's opensuse's stock driver. When the issue happens, I can't see my mouse at all -- even if I try and move it to the upper left. Pressing Ctrl+Alt+F1 drops me to a command line login. Once I enter my information I can hear the audio again but I am in still the CLI. Alt+SysReq+S does nothing at all.
EDIT 2
After running the game and getting "locked up", I hit Ctrl+Alt+F1 and was brought to a shell. I logged in and ran my display command and received the following error message:
X Error of failed request BadMatch (invalid parameter attributes)
Major opcode of failed request: 150 (RANDR)
Minor opcode of failed request: 7 (RRSetScreenSize)
Serial number of failed request: 40
Current serial number in output stream: 41
It looks like it's saying I've mistyped it or something, however I tried a couple times and I'm fairly certain my syntax was correct. I still tried going back to X with Ctrl+Alt+F7 and I was stuck in the same situation. I then went back to the console and killed the game's process, and went back to X to see what happened. The resolutions and screens were still messed up, however I had mouse and keyboard support and could use my browser.