To use my Prism2-baseed USB wireless adapter (Siemens SpeedStream), I did the following:

in /etc/networking/interfaces:
Code:
 iface wlan0 inet dhcp
Then I use the following commands to connect:

Code:
 wlanctl-ng wlan0 lnxreq_ifstate ifstate=enable
 wlanctl-ng wlan0 lnxreq_autojoin ssid=SpeedStream authtype=opensystem
 ifup wlan0
 pump -i wlan0
Of course you have to use your own SSID. Hope this works for you.