Ok, I can confirm that I also get errors on my laptop.

I just don't get it. I can boot from this livecd use fluxbox
open as many apps as I want and shut the system down.
Reboot with "home=scan"
Bamm... /media/hda_whatever/knoppix.img was not cleanly umounted. check forced.

Does knoppix.img have to created on a ext2/ext3 partition?
I have tested with NTFS and Fat32 only.

Meanwhile I'm downloading the iso again.
This time I'll choose a different server, burn to a different brand cd at the lowest speed possible
using another cd-recorder.
I'll even compare both isos and have them checked with the md5s.

As always if you got another idea to solve this just let me know

TIA
xears