title: UIPopoverController moves when I resize it
body: <p>I've got a UIPopoverController which I've been using for awhile. I'm updating my code for iOS 7 now and when I resize the popover it suddenly moves across the screen which makes for a very bad user experience. </p>
  
  <p>When I'm in portrait orientation, it doesn't happen. I tap to open the popover, then I tap the button which causes the popover to expand and everything is fine. However, if I switch to Landscape orientation and do the same thing, when I tap the button to expand the popover, then it slides over to another location.</p>
  
  <p>Here is a video showing what I'm talking about: <a href="https://vimeo.com/75632364" rel="nofollow">https://vimeo.com/75632364</a></p>
  
  <p>This the code that runs when the user taps the button that causes the resize of the popover:</p>
  
  <pre><code>- (IBAction) touchedButtonPayDownLoan:(id)sender {
  
      UIView *payOffView = nil;
      if ([self.liability isBankLoan]) {
          payOffView = self.viewPayoffBank;
      } else {
          payOffView = self.viewPayoffOther;
      }
  
      CGRect loanFrame = payOffView.frame;
      loanFrame.origin.y = self.toolbar.frame.origin.y;
      payOffView.frame = loanFrame;
      [self.view addSubview:payOffView];
      [self.view bringSubviewToFront:self.toolbar];
  
      [UIView beginAnimations:@"Show Payoff View" context:nil];
  
      NSMutableArray *items = [[self.toolbar items] mutableCopy];
      [items removeLastObject];
      [items addObject:self.barButtonFinish];
      self.toolbar.items = items;
  
      // -------- RELEVANT BITS HERE ---------
      CGRect frame = self.view.frame;
      frame.size.height += payOffView.frame.size.height;
      self.view.frame = frame;
      self.preferredContentSize = frame.size;
      // -------- RELEVANT BITS HERE ---------
  
      [UIView commitAnimations];
  
  }
  </code></pre>
  
  <p>I don't want the popover to jump positions, because that will annoy the user. Any ideas?</p>