title: API 3.8: After dragging a marker, if marker.setMap(null) then it doesn't appear more
body: <p>Using version v3.8 I got this behaviour with dragged markers.</p>
  
  <p>a) marker.setMap(map)   --> Marker on map   </p>
  
  <p>b) dragg the marker     --> It's a dragged marker</p>
  
  <p>c) marker.setMap(null)  --> hiding the marker</p>
  
  <p>d) marker.setMap(map)   --> The marker doesn't appear </p>
  
  <p>If I force use v=3.7, everything works ok, in d) the marker appears in the map.</p>
  
  <p>Greetings.</p>