I Just recently upgraded from Ubuntu 12.01 to Kubuntu 13.10. After instillation I reinstalled Mathematica 9.0.1. When I try to open Mathematica I get a blank screen and lose all functionality. Reproducible: Always
Can you elaborate on this? The linked URL (launchpad bug) suggests that X11 crashes.. That would be an Xorg bug (and is apparently related to the driver) so what makes you believe this was a KDE bug?
If you can provide the information requested in comment #1, please add it.
sorry, but without more information we cannot investigate the issue