I think that libc6 could not be replaced properly. I would suggest the following attempt.
Reboot your Knoppix into runlevel 2. You can achieve this by adding the number 2 to the list of cheat codes. Usuallyis sufficient.Code:knoppix 2
In the shell issueThis time boot into the desktop environment and try to find out whether there is any issue left.Code:chroot /UNIONFS dpkg -a --configure apt-get -f install exit reboot