Track not available/clean queue after Spotify restart

[svu]

HTC M8. Latest version of Spotify (Premium). A number of albums downloaded locally ok - and they play ok, once added to the queue.

If I pause Spotify and switch to other Android apps, at some point Spotify gets killed by the Android (typical for Android memory/task management). Then I return to Spotify - it gets restarted ok... At this point I get the popup "Track is not available", and my entire play queue is absolutely clean. Nothing. Have to populate the queue again, from the scratch. Very annoying. Any help would be much appriated.