OK
The problem is solved.
I just added the line "alias 3c95x eth0" to force onboard lan load on eth0. Now I have eth0 -> LAN and eth1 -> Wlan. I'm not sure wich was the problem but this fix it. Now I'm interested in sharing internet from a Knoppix box with a lan card and a wlan card to anther laptop with a wifi card too. I'll use a subnet for lan and other for wifi.
Wich is the best/easy way to configure the knoppix laptop to share internet and network between lan & wifi?

Thanks