Screensaver causes computer to freeze in Fedora 12
 

It's happened twice. I've come back to my computer after a couple of hours and the screen is black, but it responds to nothing, so I just power it off. What could be the problem?

It might be your videocard driver. Since you haven't provided your driver or the manufacturer of the videocard it's difficult to guess exactly.

1. As first step : Check here

2. Ask you question here