Well, sommerfee... I'm really not an expect in the UPNP area, but as far as I know..
I have asked the guys if the UPNP plugin could remember the server (because if it's your server at home why not display a ball menu for it already? instead of searching?) but it seems that this "data" about the service is a little bit more dynamic.

Anyways I will check again and if possible let this always as option (latest succeful device or local playback if the first is not available )

BR