A recent update broke KWin compositing. I can't remember exactly what packages were updated(kernel and pulseaudio are certain). I have an nvidia card. I update-ed the nvidia packages in yast, and still nothing.
When I try to enable compositing in System Settings I get the following:

Failed to activate desktop effects using the given configuration options. Settings will be reverted to their previous values.

Check your X configuration. You may also consider changing advanced options, especially changing the compositing type.
How do I fix this?