Monitor does not turn off in Gnome 3.2

Hi,

I’m using openSUSE 12.1 x64 with Gnome 3.2.
In system settings - screen, whatever option I set for “Turn off after:” item, after the designated time has passed, the monitor does not go completely off. The top bar (where the clock is) stays on. I don’t think I had this when I firstly installed openSUSE 12.1. Is this a know problem?

Best regards,
Joon