I just purchased a new Airport Extreme, plugged it up, and ran the Airport Utility on my PowerBook G4 to set it up. I added WPA2 security on the main network, and created a guest network without security. Once sending the changes, I can no longer see my main network in the Airport Utility, and cannot join that network with my Powerbook. I am able to join it using my iPhone though. Guest network works fine. Please help if possible? Im running 10.5.8.