Rendering issues of apps when minimised

Hi,

I am facing a weird problem. Whenever I exit an application like VLC/Darktable from full screen back to windowed mode, the whole application is not rendered. It just displays black areas and when I do a mouse over, bits and pieces of the applications is displayed again. I have linked the screenshots of Darktable and VLC for reference. Any help is appreciated.
In VLC, this does not affect me, but I can’t work in Darktable when I exit full screen. This hampers my photo editing workflow.

I did not have this in 12.1.

http://farm9.staticflickr.com/8081/8344530776_ecda8331cb_b.jpg

http://farm9.staticflickr.com/8083/8344530862_0cd4cea5af_b.jpg

My System:

Dell Studio XPS 1640
OpenSUSE 12.2 KDE 4.8.5
ATI Radeon 12.6 drivers