Comment 22 for bug 781402

This issue didn't initially affect me, but starting maybe a week ago (perhaps related to a compiz/Xorg update?), my machine started to occasionally refuse to return from the sleeping screen (launched from the screen saver, after letting the machine set for a while, or letting the machine sit overnight). The screen remains unpowered and all key combinations (eg alt-ctrl-F1) are ignored. If I have music streaming (eg VLC), the audio continues and the network light shows traffic.

The last time it happened, I was able to SSH into the machine. top reported that Xorg was pegged at 100%. I kill -9'ed Xorg and the screen came back alive (with the login prompt, of course). I didn't see anything particularly telling in the Xorg logs (or system logs).

I'm running Ubuntu 11.04 64-bit with Unity on a Dell Vostro 1400 laptop (with the discrete Nvidia GeForce 8400M GS running the proprietary current version 270 Nvidia driver). I am going to try solution #12 to see if it helps.