using Airport Extreme with PowerBook Pismo

I have a Powerbook G3 Pismo with the original airport card installed, which I just installed recently, and have the 4th Generation Airport Extreme that I have been using withan iPad 2. It appears that the Pismo does recognize the Airport Extreme and asks for the password to the network and when I type it in it says I have used an invalid password. I KNOW that the password is correct. The iPad 2 works flawlessly so the it is working. Is this a compatiblity problem or am I just mising something. The funny thing is that usually with an Apple product things just work but this is fairly convoluted like a Windows machine. Ugh!!! Any ideas?