title: App audio no longer working after a few days in the background
body: <p>My iOS app is an audio-led app. If I leave the app and leave multitasking on, I'm finding that if I return after a few days, it happily puts me back in the place in the app that I was, but all audio no longer works. There is no problem if I only leave it a few hours.</p>
  
  <p>It has done this lots, and I have no idea how to reproduce it. I've solved the problem for now by turning multitasking off, which is obviously not ideal. However, this means that the audio gets a full reboot each time and doesn't render the app utterly useless!</p>
  
  <p>Sorry for the vagueness, I'm a little stuck. Things I've tried: making sure all audio is released on transition of app to background, and allowing audio to run in the background (this does something else)</p>
  
  <p>Ideas?</p>
  
  <p>One solution, though not tackling the problem, would be to only allow the app to run in the background for a few hours - does anybody have an idea how to do this?</p>