title: UIView animation not working with addSubview
body: <p>I have an iPad app that is displaying a "note" (subclassed <code>UILabel</code>) with text on it. In order to navigate to the next note, I'd like it to slide it off the screen to the left while having the next one slide in from the right. I can get either animation to work, but not both at the same time.</p>
  
  <p>Here's the code in my controller:</p>
  
  <pre><code>- (void)slideOutLeft {
      // create the new note
      flSlidingNote *newNote = [[flSlidingNote alloc] init];
      newNote.text = @"blah blah";
      CGRect newFrame = CGRectMake(1000, 70, 637, 297); // off the right
      newNote.frame = newFrame;
      [self.view addSubview:newNote];
  
      // slide off the current one
      CGRect currentFrameEnd = noteLabel.frame; // noteLabel is the existing note
      currentFrameEnd.origin.x = 0 - noteLabel.frame.size.width; // off the left
  
      [UIView animateWithDuration:1.0 animations:^{
          noteLabel.frame = currentFrameEnd;
      } completion:nil];
  }
  </code></pre>
  
  <p><code>noteLabel</code> does not animate at all. If I comment out the <code>addSubview:newNote</code> part it does. I'm still relatively new at this, so it's probably just something simple.</p>
  
  <p>The problem happens whether <code>newNote</code> is animated or not (not animated in the code snippet).</p>