EDIT: that was the driver version atmelwlandriver-ss-20030613.tar.gz. today I have tried the 2.1.2.2 and it says "blabla usbvnetr was compiled for 2.4.20" which, I think, the problem is. I will see whether I will be able to install the 2.4.21-xfs sources.
Yeah, i have been hunting for those kernel sources myself. However today a thought occuered to me. The linux cd has all the source so i think that (after checking around a bit) that the atmelwlandriver file just needs to be installed in the same directory tree where the folder for the knoppix source code is. I think that is usr/src/ so i will try that out later on and let you know how it went.