title: Animated AnnotationView disappears while zooming the mapview?
body: <p>I add a <code>CABasicAnimation</code> to the <code>AnnotationView</code> layer to simulate a car moving on the mapview.</p>
  
  <p>This works fine until I try to zoom in or out the mapview when the animation is in progress. </p>
  
  <p>I found the animating annotation view disappears when zooming the mapview!!</p>
  
  <p>I guess this may be caused by that the layer associated the animation object has been removed when zooming mapview.</p>
  
  <p>I try to solve this by stopping the animation when zooming. but the result is not good. The car seems jump to target point.</p>
  
  <p>Anyone has ideas about this?</p>
  
  <p>Anyone knows how to make the animation still running when zooming the mapview?</p>