title: MPMoviePlayerViewController lock screen playback controls not working
body: <p>I have an app that has the following setup:</p>
  
  <p><strong>URMoviePlayerViewController extends MPMoviePlayerViewController</strong></p>
  
  <ul>
  <li><p>has the method remoteControlReceivedWithEvent:(UIEvent *)event implemented, as well as:</p>
  
  <pre><code>(void)viewDidLoad
  {
      [super viewDidLoad];    
      [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
      [self becomeFirstResponder];
  }
  
  (BOOL) canBecomeFirstResponder
  {
      return YES;
  }
  </code></pre></li>
  </ul>
  
  <p><strong>URPlayerViewController has the URMoviePlayerViewController as a property</strong> </p>
  
  <pre><code>    @property (nonatomic, strong) URMoviePlayerViewController *player;
  </code></pre>
  
  <ul>
  <li><p>player is initialized when a call to play a clip of audio is made; if it is already initialized, it does not re-initialize the player</p></li>
  <li><p>URPlayerViewController has a view that is a custom player with play/pause, next/previous controls that is initialized and added to the subview in the viewDidLoad method</p></li>
  </ul>
  
  <p><strong>URAppDelegate has URPlayerViewController as a property</strong></p>
  
  <pre><code>    @property (nonatomic, strong) URPlayerViewController *playerViewController;
  </code></pre>
  
  <ul>
  <li><p>playerViewController is initialized in application didFinishLaunchingWithOptions</p></li>
  <li><p>playerViewController's view is added to the <em>window</em> - so that the custom player is visible throughout the app</p></li>
  </ul>
  
  <p><strong>Problem:</strong></p>
  
  <p>Everything usually works well. Every now and then on the lock screen the playback controls (play/pause/next/previous) stop working. remoteControlReceivedWithEvent never gets called. I have not been able to reproduce this consistently.</p>
  
  <p>Any advice or ideas on debugging this issue around playback would be great as I am not able to consistently reproduce this issue. Thanks!</p>