I need some help with my AirPort Setup. As you can see, a current generation AirPort Express is connected by wire to my router. Both the older AirPort Express (which does support 802.11n) and the AirPort Extreme (A1354) are set to extend the network. But one of them doesn't want to extend it. If I restart the main Express, the two other base stations sometimes switch place, with the Express extending the network and the Extreme showing the warning. So all the base stations seem to work fine by themselves. Any ideas why this is and how I can solve it?