I'm having intermittent problems where the screen will freeze in Ubuntu. I've tried using Ctrl + Alt + Backspace to restart the X-server, though this does nothing. When the freeze occurs, there's a small square of black dashes around the mouse pointer - maybe 1 inch in size. These dashes look a lot like a 2d barcode. The rest of the screen looks normal, but I can't move the mouse and none of the keyboard shortcuts work to do anything. However, music that I begin playing before the freeze continues to play, which seems to indicate it hasn't stalled up completely.
I've noticed a similar freezing problem when I'm using Windows 7. That is, I see the same barcode like dashes around the mouse pointer when it freezes up. So I'm guessing it's either a driver or hardware problem. I thought if it was a hardware problem though, the whole computer might stop working (i.e. music would stop playing)? The video card I am using is an Nvidia, and I believe it's in the 7600 range. In Ubuntu I have the drivers for the card set to the latest available (proprietary). Ideally I'd like to be able to continue using the proprietary drivers. Is there any known issues with the drivers for this model graphics card, or has anyone experienced the same problem and knows how to fix it?