Track sometimes not available, not always.

[Veneficus]

I am using the Spotify client on my Onkyo receiver. On the Spotify desktop application I create playlists, which are then synced.

At random moments, when trying to play tracks on my receiver, some tracks are displayed as 'Track not available" , while they are playable at other moments, and even at the same moment on the desktop app. So the tracks are in the Dutch catalog, and even playable at other times, but just sometimes randomly they are not. This is really starting to piss me off...