title: UINavigationBar disappearing on presentViewController:animated:completion
body: <p>I've been beating my head against a wall for the better part of a week trying to figure out what's going on with this error, but I cannot figure anything out. I've read through all of the view controller documents on Apple's developer stuff, looked through countless articles here, etc.</p>
  
  <p>I've got 3 view controllers: a base view controller, an image editing controller (allows user to zoom in/pan through an image, and on pressing okay, save the image within bounds, return image to the base view via a delegate method, and push it to the last view controller), and finally a BigPictureViewController where the user interacts with the image he saved.</p>
  
  <p>On calling presentViewController:animated:completion from the base view controller, the navigation bar appears for a split second, then disappears. I've completely gutted the final view controller so that it just displays a blank screen identical to when you first create a view controller, but the navbar still disappears, so I know it's not something in the view controller's coding.</p>
  
  <p>Here's the delegate from the image editing controller (contained in the base view controller):</p>
  
  <pre><code>#pragma mark - camera view delegate
  -(void)cameraView:(CameraViewController *)camView didReturnWithEditedImage:(UIImage *)image
  {
      theImage = image;
      BPVCFlag = YES;
      [self.navigationController popViewControllerAnimated:YES];
  }
  </code></pre>
  
  <p>Next, in the base view controller's viewWillAppear method, I check for the flag to toggle the segue:</p>
  
  <pre><code>-(void)viewWillAppear:(BOOL)animated
  {
      [super viewWillAppear:animated];
      if (BPVCFlag)
      {
          BPVCFlag = NO;
          BigPictureViewController *bpvc = [[BigPictureViewController alloc] init];
          UIStoryboardSegue *seg = [[UIStoryboardSegue alloc] initWithIdentifier:@"pushitrealgood" source:self destination:bpvc];
          [self prepareForSegue:seg sender:self];
      }
  }
  </code></pre>
  
  <p>Lastly, the prepareForSegue method:</p>
  
  <pre><code>-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
  {
      NSString *id = [segue identifier];
      if ([id hasPrefix:@"pushit"]){
          BigPictureViewController *bpvc = segue.destinationViewController;
          bpvc.imageFromLibrary = theImage;
          [self presentViewController:bpvc animated:YES completion:nil];
      }
  }
  </code></pre>
  
  <p>I've tried presenting it from self.navigationController, etc., and I can get it to stick with a different navigation controller if I use</p>
  
  <pre><code>UINavigationController *navCon = [[UINavigationController alloc] initWithRootViewController:bpvc];
  [self.navigationController presentViewController:navCon animated:YES completion:nil];
  </code></pre>
  
  <p>but that seems like an extremely hacky way to do it, and doesn't actually solve the problem, just circumvents it.</p>
  
  <p>Sorry for the wall of text, but I'd rather be thorough than leave people in the dark.</p>
  
  <p>TL;DR on presentViewController, the navigation bar pops up for a split second and then disappears~</p>
  
  <p>Thanks in advance for any help/tips!</p>