title: Google API V3: Problem with polygon mouseover events if groundOverlay is also defined
body: <p>I am using Google API V3 and I want to have a ground overlay and on this overlay a polygon which changes color on mouseover. The mouseover event works fine as long as no ground overlay is defined. But if the ground overlay is present the the color does not change on mouseover.</p>
  
  <p>Any suggestions?</p>
  
  <p>Here is an example:</p>
  
  <pre><code>var newark = new google.maps.LatLng(40.740, -74.18);
  var imageBounds = new google.maps.LatLngBounds(
  new google.maps.LatLng(40.716216,-74.213393),
  new google.maps.LatLng(40.765641,-74.139235));
  
  var myOptions = {
  zoom: 13,
  center: newark,
  mapTypeId: google.maps.MapTypeId.ROADMAP
  }
  
  var map = new google.maps.Map(document.getElementById("map"), myOptions);
  
  var oldmap = new google.maps.GroundOverlay(
  "http://www.lib.utexas.edu/maps/historical/newark_nj_1922.jpg",
  imageBounds);
  oldmap.setMap(map);
  
  //Points to create polygon
  var points = [
  new google.maps.LatLng(40.735657,-74.172367),
  new google.maps.LatLng(40.743588,-74.179498),
  new google.maps.LatLng(40.732878,-74.182777)
  ]
  //Create Polygon
  var poly = new google.maps.Polygon({
      path: points,
      map: map,
      strokeColor: '#ff0000',
      strokeOpacity: 1,
      strokeWeight: 1,
      fillColor: '#ff0000',
      fillOpacity: 1
  });
  
  //poly changes color on mouseover
  google.maps.event.addListener(poly, 'mouseover', function() {
      poly.setOptions({
          strokeColor: '#0000ff',
          fillColor: '#0000ff'
      });
  });
  
  //poly changes color back on mouseout
  google.maps.event.addListener(poly, 'mouseout', function() {
      poly.setOptions({
          strokeColor: '#ff0000',
          fillColor: '#ff0000'
      });
  });
  </code></pre>