I also had a problem installing 3.6 whereas there was no problem with 3.3.

The command recommended in documentation for installing 3.6 to a HD is
' knoppix-installer ' but nowhere in the all the documentation is it mentioned that it depends on what directory is active in the command line.

Just on a suspicion, I did a
' whereis knoppix-installer '
and it came back with ' /usr/sbin/knoppix-installer ' .
So, I ran this command:

sudo /usr/sbin/knoppix-installer

and there it was----the Installation Wizard that lets you set up the partitioning and installation.
knoppix 3.6 now works beautifully, thank you.

I'm wondering if perhaps some issues of the KNOPPIX 3.6 Cds default to a different location for the knoppix-installer.