I have the same onboard 3COM Gigabit LOM 3C940 with my Asus P4P800 mainboard. Knoppix doesn't detect it on boot. So I should use modprobe to load the module sk98lin to make it work. You may try to do the same.

su
modprobe sk98lin

For the sound (ADI AC 1985 SoundMax), I have to use the cheatcode knoppix alsa on boot.

It's really bad that Knoppix doesn't detect theses two pieces on boot while others (MandrakeMove 1&2, Suse Live or Lindows Live) do it without any struggle.

Hope this helps