I’m running openSUSE 11.2 x64 with a Geforce 7300GT video card and just recently I noticed that my taskbar (using KDE 4.3.1 here) is flickering like mad. I thought at first it was a mouse/USB-related problem but I narrowed it down to the compositing functionality in KWin. When I disable compositing the taskbar flicker goes away but returns immediately when I re-enable compositing. I’ve tried rebooting, re-installing the Nvidia drivers and reconfiguring the display via Sax2 - all to no avail.
Any ideas ?
I really hope this isn’t a hardware issue with my video card.
Do you have anything enabled, I mean special widgets?
Creating a new user and then enable desktop effects is a troubleshooting route. Don’t change anything else.
If it happens there it eliminates user settings and points more to hardware issues.
But then try knocking off some of the effects to see if it something in particular.
No special widgets here - just the usual (clock, calculator, temperature monitor).
I created a new user and desktop effects were enabled by default - no flickering at all. The problem must lie with my desktop configuration. I tried disabling most of the desktop effects but this didn’t help 
The only thing that stops the taskbar from flickering is turning off compositing.
I seemed to have solved the problem by removing the taskbar and creating a new default one.