I just bought my Airport Extreme with the idea of connecting my iMac, PS3 and XBox 360 to an existing wireless network. I go through the auto setup, but the Airport Utility is asking if I'd like to either: Connect to the internet using Ethernet or replace an existing network device. I don't want to either, just connect the three devices to the LAN ports, then use the wireless to connect to an existing network. I'm assured it should work, but for the life of me, I can't get it to. I can connect to the network, using the built in iMac airport crad, so I know the wireless network is okay, but for some reason I just can't get the Extreme to connect to it. Any suggestions, please ?