Have you followed your own instructions on http://www.knoppix.net/forum/viewtopic.php?p=36905 ?

please follow the steps of remastering given on knoppix.net
Now that you've got what you deserved for such an useless answer , I have isolated the problem to a corrupt KNOPPIX file being generated. This is the process:

1- Booting from and old KNOPPIX, we remaster it. The KNOPPIX file is created with an old cloop-tools.

2- Now we boot from this remastered knoppix. The old cloop.o loads and "old format" KNOPPIX file. We remaster it again, but this time we are putting together the miniroot.gz containing an old cloop.o, and a KNOPPIX file generated with the new cloop.

3- Our newly generated KNOPPIX can't be loaded by the cloop.o module contained in the miniroot

Solution: inside a working KNOPPIX, update the copy on HD that you are going to repack, compile the sources of the latest unstable version of cloop.o, and put it inside miniroot.gz