title: Navigation buttons missing from UIImagePickerController when added to UIPopoverController
body: <p>Got a strange problem. The cancel button that normally is shown at the navigation bar when you add a UIImagePickerController is missing when I add it to my UIPopoverController.</p>
  
  <p>I have tried to subclass the UIImagePickerController and add a navigation button to the navigation bar myself, but it did not show up.</p>
  
  <p>If I select my camera roll the back button gets automatically added, but the cancel button is still missing.</p>
  
  <p>Anyone know what could cause this?</p>
  
  <p>Here is the code i use. Note that _popOver is the instance of my UIPopoverController.</p>
  
  <pre><code>UIImagePickerController *picker = [[UIImagePickerController alloc] init];
  picker.delegate = self;
  picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
  [_popOver setContentViewController:picker animated:YES];
  </code></pre>