100% CPU usage with GTK applications

[Stefan Heinrichsen <gelbemauer gmx de>]

Hello,

I already posted that in the gentoo-forums but got no helpfull reply.
in any gtk application I use I always have 100% CPU usage when scrolling, 
moving windows on top of the application or something else.
When I use qt application I have no problems. (Example: Opening a pdf in 
acroread and do scrolling => ~66% CPU usage form X and 33% CPU usage from 
acroread, using kpdf => 5% CPU usage from X and 0,5% CPU usage from kpdf). 
Even typing in Open-Office makes X using up to 15% CPU. Nvidia driver is 
installed correctly (3D games are working without any problems). 
I have installed gtk+ 1.2.10 and 2.12.1 using the default theme.

Stefan