title: Strange issue with UIDocumentInteractionController
body: <p>I don't know what wrong with this code but everytime when I run the app, after the Menu is shown, the app crash.</p>
  
  <pre><code>NSString * path = [[NSBundle mainBundle] pathForResource:@"tung" ofType:@"doc"];
  
  UIDocumentInteractionController *docController = [UIDocumentInteractionController interactionControllerWithURL:[NSURL fileURLWithPath:path]];
  
  docController.delegate = self;
  
  //[docController presentPreviewAnimated:YES];
  
  CGRect rect = CGRectMake(0, 0, 300, 300);
  [docController presentOptionsMenuFromRect:rect inView:self.view animated:YES];
  </code></pre>
  
  <p>Error I got: </p>
  
  <blockquote>
    <p>*** Terminating app due to uncaught exception 'NSGenericException',
    reason: '-[UIPopoverController
    dealloc] reached while popover is
    still visible.'</p>
  </blockquote>
  
  <p>What should I do now ?</p>