Trouble Using Wep


I have a WLAN using a Netgear router, it was encripted with a 64bit password, it is set to "Automatic". I have had no trouble setting up the connection for my 3 PC's and my PSP, but when I try to set up my G4 iBook, it gives me a message saying there wan an error connecting, or it constantly says the password is wrong...

My ISP has a dynamic IP, and before I encripted the WLAN I had no trouble connecting. HOw can I configure my Mac to work with the WLAN without compromising it's current settings?