title: Modal View Controller making background black
body: <p>I am launching a Modal View Controller from a view controller.  Everything in the modal view controller is displayed fine, except that the parent view controller goes black.  When the modal view controller is dismissed, the parent is drawn.  Can anybody point me where I am going wrong?  Here is the code I am using:</p>
  
  <pre><code>modalVC.modalPresentationStyle = UIModalPresentationFormSheet;
  self.navigationController = [[UINavigationController alloc] initWithRootViewController: modalVC];
  
  [currentViewController presentModalViewController: self.navigationController animated: YES];
  self.navigationController.view.frame = CGRectMake(200, 200, 320, 540);
  </code></pre>