MPMoviePlayerController stops after four seconds - objective-c

Question

I am trying to set up a very simple video player. (iOS 5.1, Xcode 4.3.1)
-(void)playMedia {
NSString *movieFile = [[NSBundle mainBundle] pathForResource:#"Movie" ofType:#"m4v"];
MPMoviePlayerController *moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:movieFile]];
[moviePlayer prepareToPlay];
moviePlayer.view.frame = self.view.bounds;
moviePlayer.scalingMode = MPMovieScalingModeAspectFit;
moviePlayer.movieSourceType = MPMovieSourceTypeFile;
moviePlayer.fullscreen = YES;
moviePlayer.controlStyle = MPMovieControlStyleFullscreen;
[self.view addSubview: moviePlayer.view];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playMediaFinished:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:moviePlayer];
[moviePlayer play];
}
It works fine when called, but it only plays for four seconds, then a black screen appears. If I tap the screen during playback, it will play the entire sequence. If I stop tapping the screen for four seconds, the black screen appears.
What am i missing?
Kurt
Edited version plays fine.
In the interface file:
#property (nonatomic,strong) MPMoviePlayerController *myMovieController;
In the .m file:
-(void)playMedia {
NSString *movieFile = [[NSBundle mainBundle] pathForResource:#"Movie" ofType:#"m4v"];
MPMoviePlayerController *moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:movieFile]];
[moviePlayer prepareToPlay];
moviePlayer.view.frame = self.view.bounds;
moviePlayer.scalingMode = MPMovieScalingModeAspectFit;
moviePlayer.movieSourceType = MPMovieSourceTypeFile;
moviePlayer.fullscreen = YES;
moviePlayer.controlStyle = MPMovieControlStyleFullscreen;
self.myMovieController = moviePlayer;
[self.view addSubview: self.myMovieController.view];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playMediaFinished:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:moviePlayer];
[self.myMovieController play];
}

Answer 1

If you're using ARC I believe you need to retain the outer moviePlayer. I just assigned it to a new property myself. HTH

Answer 2

The solution is that the player would have to be an instance variable or property of the view controller.
ie We must use the instance of MPMoviePlayerController
#property (nonatomic,strong) MPMoviePlayerController *myMovieController;