Has nobody got any ideas?! I have a more complex - and confusing - setup now, but perhaps the new variables will shed some light, and cause someone to have a helpful brainwave...

At home we now have one Sony STR-DN1020, two Synology DiskStations (my DS211j, running DSM 4.0-2228, and my Dad's DS411j, running DSM 4.0-2198; both are running Audio Station 3.0-2205, iTunes Server 1.1-2256, and Media Server 1.0-2252), and two iPads (both running iOS 5.1.1 and v. 4.0-097 of the Synology DS Audio app). It seems that, if either of us uses the iPad app to send a song from *my* NAS to the STR-DN1020, it generally *works*, but only if we select the song from a shared playlist or a folder (but not if we just select the same track from e.g. the artists section). This does not work if we try to do the same from my Dad's NAS. If no music was playing when we try to play something from his, it just says 'cannot play'. Something very curious happens, however, if one of us is playing a song from my NAS on the STR-DN1020, and the other then tries to send a song from his NAS to the same device: the 'cannot play' message pops up for a second or two, then _the next song on MY playlist starts playing_. To qualify: if I am playing e.g. song 4 on one of my playlists from my NAS, and my Dad tries to play one of the songs from his NAS, the result is that song 5 on MY NAS starts playing!!

Oh, and to make matters more confusing, songs will only play if a playlist has more than one song.

So, any thoughts, anyone?! Why does sending a request to play a song from one NAS work, but only under certain circumstances - and why does sending an identical request to play a song from the other NAS cause the previously playing playlist to skip forward one track?

Any thoughts at all would be very gratefully received. Until then, we'll carry on testing...

Thank you!

Chris