Sounds like a graphics driver crash. IIANM you have an intel chip, the intel driver shipped has some bugs (can cause crashes with compositing).
A new version is already in the update repo, so I would suggest to just boot to recovery mode and install all updates. (“zypper up”, YaST->Online Updates or Apper)
Chances are that normal mode works then…
Oh, and ~/.kde/share/config/kwinrc is for KDE3, which doesn’t even have compositing. So this won’t have any effect of course.
For KDE4 you would have to edit ~/.kde4/share/config/kwinrc on openSUSE…