[wlug] wireless connection

My landlord has agreed to share his wireless connection (for a fee) with me and has provided me with the password. If I boot into windows, add the password it all works but with Ubuntu I cannot get a connection. so far I tried ascii and hexadecimal but no connection i have the networking set to dchp the router address is 192.168.1.254 do I need to turn off dchp and use a fixed address? Or is there some other thing I may have missed?