I've just purchased two AirPort Express, installed them and they appeared in the Airport Utility (latest version) but after a few minutes they disappear and the only option I get is to forget them. In that five minutes I can sleect them in Itunes, but if I deselect them I don't get the option to reconnect - error 15006 and the multiple speaker option disappears from Itunes. After 10 minutes they both reappear in the Airport Utility and in Itunes, then disappear after a few minutes etc.etc...
Both AE are currently sitting 2 feet away from my router
Router is running in WPA/WPA2 mode
I have updated the firmware on them both - no difference
I have given them static IP addresses
Turned off IPv6
Only way I can see them both in itunes multi speaker with volume pop-up is if I name them exactly as itunes sees them Base Station xxxxxx, otherwise I can select them individually from the dock symbol