See the image :
http://img210.imageshack.us/img210/7274/zrzutekranux.jpg
As far as I remember, it occured from the very first moment I installed opensuse. But I might be wrong. It happens both with kwin and compiz as compositing managers.
Any suggestions?
It does happen. But it is much improved in 4.2.1
And I understand when 4.3 is released - which will use qt45 - all will/should be good.
I know some users are already using qt45, but for me breaks one or two things and the build service recommendation is not to use qt45 with 4.2