Google Maps - Custom Icon & Popup overlay issues

I've looked at as many examples as I could find, and they all show me the same thing. I can't figure out what I'm doing wrong. I'm using a custom icon, placing it on the map, and adding a popup overlay to it. The custom icon will display, but the popup won't. If I don't use a custom icon, the popup and icon work fine.

        function initialize() {
      if (GBrowserIsCompatible()) {
        var map = new GMap2(document.getElementById("map_canvas"));
        map.setCenter(new GLatLng(43.220689, -87.974396), 11);

  var pin1 = "http://chart.apis.google.com/chart?chst=d_map_xpin_letter&chld=pin_star|1|FF0000|000000|00E5FF";
  var shadow = "http://www.google.com/mapfiles/shadow50.png";

  var Icon1 = new GIcon();
        Icon1.image = pin1;
  Icon1.shadow = shadow;
        Icon1.iconAnchor = new GPoint(6, 20);

  function createMarker(point, html) {
   var marker = new GMarker(point,{clickable:true, icon:Icon1});
   GEvent.addListener(marker, "click", function() { marker.openInfoWindowHtml(html); });
  return marker;
  }

  var point = new GLatLng(43.308926, -87.961113); 
  var html = "Some stuff.";
  var marker = createMarker(point, html);
  map.addOverlay(marker);

        map.setUIToDefault();
      }
    }

Please help! I have no idea what else to look at. Something is causing the popup to break when the custom icon is there. But the icon shows fine, so it开发者_如何学Go's formatted properly.

Thanks