Bug#600846: In Kubuntu 10.10 with kernel version 2.6.35 bug also exists.
What I forgot to mention:
I tried the new Kubuntu 10.10 with kernel 2.6.35 and the bug there also
Immediately after the installation without any configuration I tried the
5 times and it seemed to work fine.
After doing some configurations (e.g. mounting two additional drives)
stopped working again.
The only notable change to the system that I remember was changing the
default to the Sun JRE.