Comment 23 for bug 762918

One other oddity: I just had my machine lock up despite having deactivated the screensaver.

The lid on my laptop was closed for approx 2 hours, and I was running the Transmission bittorrent client minimized. The power setting to blank the screen may be to blame, since the gnome-screensaver process is still running and may be what is blanking the screen. It may in fact be related to having the Transmission client running, though I've had the machine running overnight in the same configuration and had no issue.

Just one other small bit of info.