I have a wireless network that I've been testing Knoppix with and I keep encountering problems with encryption.
The wireless router has default values and DHCP disabled, I assign an IP address to a client in knoppix and can ping the wireless router.
I can set the SSID to hide on the wireless router and when I shutdown both interfaces (eth0, wifi0) then enable them again and ping the wireless router it works.

Then I set the encryption on the AP to 64 bit with ASCII phrase "passw".

In knoppix I do iwconfig wifi0 key sassw[4] to set the encryption to "passw" on key 4, I've tried this on both interfaces, both when shut down and enabled again but still I can't ping the wireless router.
When I do iwconfig wifi0 the config displays the IP address, encryption as hashes, the correct MAC for AP so I don't know why it's not working.

The wireless client card is cisco aironet, the problems only arise when trying to use encryption.

Any help appreciated.