ios MPMoviePlayerController movie controls do not show the correct time.

Question

I have following code that I use to play a selected portion of a movie clip. The movie plays okay. But the scrubber bar does not reflect the correct start stop time. Also, the forward and rewind buttons take the clip beyond the segment that was specified. Why is this and can we fix it?

TIA.

MPMoviePlayerViewController *mp =
[[MPMoviePlayerViewController alloc] initWithContentURL:[NSURL fileURLWithPath:movieFile] ];

[mp.moviePlayer setInitialPlaybackTime:21];
[mp.moviePlayer setEndPlaybackTime:48];

[self presentMoviePlayerViewControllerAnimated:mp];
[self shouldAutorotateToInterfaceOrientation:YES];
//NSLog(@"Movie Player Controller View = %@", mp.moviePlayer.view);
//NSLog(@"Movie Player Controller Parent View = %@", mp.parentViewController);

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(moviePlayBackDidFinish:)
                                             name:MPMoviePlayerPlaybackDidFinishNotification
                                           object:[mp moviePlayer]];

[mp.moviePlayer play];