Hello,
I'm putting together a custom project to stream movies/music in the car for road trips. I've set up a Raspberry Pi with XBMC as the UPnP server and a wireless network card acting as an access point. If I boot up without the Ethernet cable plugged in I can browse content and start loading a movie, but it never plays. The second I plug the Ethernet cable in the movie starts playing. I can then disconnect the cable and everything continues to work fine - I can even introduce new devices and Airplayer works on them too.
As a test, I pulled an old router out of the basement and used it to give an address to the Ethernet port on the Pi (again, no Internet connection) but the results were the same.
I know the setup works because while Airplayer is hung loading the movie I can stream to my PS3 and to XBMC on an Android tablet. I can also play movies in another (unnamed) iOS UPnP player but I really prefer Airplayer to the other UPnP clients.
Any ideas? Does Airplayer somehow require a WAN/Internet connection, or at least think there is one?