Comment 4 for bug 357577

I recreated the problem several times (each time I enable desktop effects), but all times resulted in a completely nonresponsive system - the mouse cursor moves, but neither keyboard nor mouse actions do anything. so I couldn't get to Xorg.0.log from within the problem state, but I've attached one from the next boot in case there's something useful about the system configuration there. I haven't modified xorg.conf manually, but I've used nvidia-settings which modifies it, I'll attach it as well.

If I manage to get to the 100% cpu scenario again in which I can ever so slowly get to a console, I'll try to grab the logs - but I don't know how to recreate it specifically - as before, each time I turned on desktop effects resulted in one of the 3 different corrupt/stuck states in the original report.

for the benefit of others having the problem and reading this report, the way to get back to a usable system:

1. reboot
2. do not log in to KDE, rather press ctrl-alt-F1 and log in at the console
3. edit the configuration file ~/.kde/share/config/kwinrc (e.g. using vi)
4. under the [compositing] header, find the line reading "Enabled=true" and change it to "Enabled=false"
5. save the file
6. reboot (from the console, type "sudo reboot" and enter your password)
7. now u can log in normally (with desktop effects disabled)