第二次调用avaudioplayer->exc_bad_access(代码已发布,我错过了什么?)

我用这个代码在每次通话中播放不同的MP3文件。第一次通过效果很好。第二次碰撞,如下所示。

h

AVAudioPlayer *player;
@property (nonatomic, retain) AVAudioPlayer *player;

m

-(void)load:(NSURL *)aFileURL {
 if (aFileURL) {

  AVAudioPlayer *newPlayer =
  [[AVAudioPlayer alloc] initWithContentsOfURL: aFileURL
                      error: nil];

  [aFileURL release];
  self.player = newPlayer; // CRASHES HERE EXC_BAD_ACCESS with second MP3a
  [newPlayer release];

  [self.player prepareToPlay];
  [self.player setDelegate:self];
 }   
}

我知道我一定错过了什么,有什么想法吗?