Gnome-Shell's background flashes black from time to time

[Bazon]

Form time to time, my Gnome-Shell-background flashes black for half a second.
Does anyone now how to avoid it?
Is there a bug report about that?
Haven't found that yet...

[Bazon]

*up*
problem still occurs

[Bucky Ball]

sorry, this is a unrelated question
I am new to this forum. how to post question here?
I want to set system to shutdown after 2 hours in inactive mode. but at the system settings for power, the options for power plugin (not batter),

1 suspend when inactive for => 1 hour
2 when lid close => suspend

I want to shutdown when in inactive mode for 2 hours

Go to the forum you want to post in and click 'New Thread' at the top left of the screen. Your issue has nothing whatsoever to do with the original OP's so I have asked mods to move to a separate thread. Hijacking another thread is not the answer and two problems on one thread gets confusing for everyone (and cuts your chances of help as this thread title has nothing to do with your issue).

Use a descriptive thread title and give all relevant information (release and anything else you can think of).

As for the original OP's problem; are you using 12.04 LTS by any chance?

[Bazon]

OK, switched to 12.04 beta, doesn't happen there anymore...
(...also, that solved some kind of mouse-lacking I experienced in Gnome Shell in 11.10.)