Ok, now I've tested it a little bit. I always get the following error after welcome-screen, no matter what I do:

-x-x-x-
You have /dev/
Can't make sub-window at (33,12),
size (1,54)
-x-x-x-

My Partitions are:

primary 7,8GB ext3
extended
logical 0,2GB swap

I tried the following:

- call knx-hdinstall with mounted partitions
- call knx-hdinstall with unmounted partitions

I even deleted all partitions and tried to run knx-hdinstall, but I always get the same error.

What's wrong? Perhaps my harddisk is too old for Knoppix, but that would surprise me. Running 'badblocks' gives me no bad sectors....