Thank you Gilles, it works! hdparm -t shows that my hard drive and
my memory key are both running at their correct speeds. The grub menu
is different from regular Knoppix, but the "e" command let me add
the home=/mnt/sda1/knoppix.img cheat code.

Also, thank you for providing the exact mkisofs command. This will be
helpful if I try to do my own further customization.

I hope that Klaus will include your fix in the next release.