Window (re)draw problems after update (KDE)

[sidamos]

I upgraded my system and now I have redraw problems. For example, I suddenly see parts of Chrome inside Thunderbird or LibreOffice. Happens sometimes when I minimize Chrome and sometimes just by itself, without me doing anything with the windows. Sometimes I also see flickering.

I can fix it by closing all windows, but this is not easy always, because when it happens, I often do not see close buttons and closing from the task bar also does not work.

I have desktop effects off and I am using a 2 screen configuration (2 seperate X screens, :0.0 and :0.1). I never had something like this until the recent update.

Upgrade was >200 packages, but these are IMHO the most notable:
* KDE 4.11.5 -> 4.12.5
* nvidia-drivers 331.49 -> 334.21-r3
* Chrome 34.0.1847.116_p1 -> 35.0.1916.114_p1
* xorg-server 1.14.3-r2 -> 1.15.0
* thunderbird 24.4.0 -> 24.5.0

I already downgraded:
* Chrome to 34.0.1847.116_p1
* nvidia-drivers to 331.67

Downgrading xorg-server or KDE is not so easy, I think.

It is now happening perhaps a bit less often, I think, but it still happens.

Any hints or suggestions would be greatly appreciated. Thanks!

[sidamos]

In the meantime, I enabled desktop effects and did not have any redraw problems since then.

This points to a bug in kwin, I guess, which only happens with desktop effects off.