I have an AirPort Extreme (n, 1st gen.) and several AirPort Expresses (g), all connected through their Ethernet ports to my network. The Extreme is used to "create a wireless network" and one of the Expresses is used to "participate in a WDS network", while the others have their antennas turned off. Every few weeks, the Express that is extending the network (along with its signal) vanishes from the network and needs to be powercicyled to reconnect. Why would this be happening?
Save configuration and replace it with another one from those that have their radios disabled. Maybe this will be enough of a solution.
Why would this be happening? I don't know but it's either power supply or its OS crashing. Or both.