Okay so I just finished getting my D-Link DWL-G520 wireless card working in kanotix and this should work just as well in knoppix 3.9, this should save alot of you some trouble.

First open KWifi Manager and it should show the laptop without a red line through it.
Second click on the icon beside the KMenu and goto Network/Internet > Wavelan configuration
type in your ssid and any other things like your wep code if you have it on (i sugest having a basic router set up so that all you have to type in is the ssid to make it easier to start)

after that you should be connected to the router but not getting an IP address
so open your konsol and become root
type in $dhclient wlan0
(you should now have an ip and be connected to the internet)
-now to set it up so it starts with your box so that you don't have to config it everytime

edit this file /etc/network/interfaces

under the line that says if face lo inet loopback type this in

auto ath0
iface ath0 inet dhcp
wireless-essid MYESSID
wireless-channel auto
wireless-key MYSECRETKEY


There you go you should be working now one this is saved
Now your network will come up at start up
enjoy!

Moved: This thread is more suitable in Wireless Forum and has been moved accordingly to help your thread/question get the exposure it deserves.