Comment 4 for bug 758214

To complete my previous comment #2, I got an other case when I wait gnome to lock the screen:
- wait until the monitor is going to sleep
- wait some extra time that gnome-screensaver lock the session
- move the mouse
- wait that the monitor display an image
=> See that the image is the same that before the monitor went to sleep. The cursor can move but the entire desktop looks like a wallpaper
- go to first console, log in
- kill -9 `pidof compiz`
- go to X console
- see gnome lock screen being redrawn
=> The desktop can be use normally (after unlocking gnome session)