I have a Logitech 4000 pro with a asus A7V8X motherboard that has USB 2.0 and I can't put my camera working.
This was writen in the Linux usb

If you're a 2.4 user, use 2.4.22-pre1 or later. That closely matches the Linux 2.6.0-test EHCI code, which seems to resolve the worst problems reported. (VT6202 problems still seem to remain, especially on 2.4 kernels.) Remember this is still classified as 'experimental'.

I hope that the new version for knoppix comes already whit the new kernel version.