Hi there,
I've installed a clean version of kubuntu 8.10 on my vaio laptop. Surprisingly, sometimes KDM crashes unexpectedly, the monitor goes blank, and the log-in screen appears automatically (without system restart, just like when the KDM restarts). This happens from time to time. Besides, when I'm in, sometimes my monitor blinks, the icons in sys tray move a little at their place, and sometimes I receive an error saying an external monitor disconnected although my laptop isn't plugged in to any external displays. I had several versions of kubuntu before, Feisty, Gutsy, and Hardy. They all were based on KDE 3.5 and there were no problem with them. This is the first time I installed KDE 4 and believe that it's a KDE bug. Thanks for your help.
Could you attach copies of your /var/log/Xorg.0.log and var/log/