[OpenLayers-Dev] Vector layer marker drifting with Google base map

[Sean Gillies]

Hi all,

I'm trying to overlay a point vector layer symbolized with drop shadow
markers over a base Google layer. Things look fine, the marker is where
I expect it, until I pan and then the position of the marker begins to
drift approximately half height of the marker in the panning direction.
I'm using the javascript served from openlayers.org/api/OpenLayers.js.

Known bug? Programmer error? Script below:


<script type="text/javascript">
  var map, base, marker, coords;
  var SHADOW_Z_INDEX = 10;
  var MARKER_Z_INDEX = 11;

  function init() {
    map = new OpenLayers.Map('map');
    base = new OpenLayers.Layer.Google(
                "Base", {
                    isBaseLayer: true,
                    type: G_PHYSICAL_MAP,
                    }
                );
    marker = new OpenLayers.Layer.Vector(
                "Marker",
                {
                    styleMap: new OpenLayers.StyleMap({
                        externalGraphic:
"http://openlayers.org/dev/img/marker-gold.png",
                        backgroundGraphic:
"http://openlayers.org/dev/examples/marker_shadow.png",
                        backgroundXOffset: 0,
                        backgroundYOffset: -7,
                        graphicZIndex: MARKER_Z_INDEX,
                        backgroundGraphicZIndex: SHADOW_Z_INDEX,
                        pointRadius: 10
                    }),
                    reproject: true,
                    isBaseLayer: false,
                    projection
                    rendererOptions: {yOrdering: true}
                }
            );
    coords = pleiades_oljs.centroid.coordinates;
    map.addLayers([base, marker]);
    map.setCenter(new OpenLayers.LonLat(coords[0], coords[1]), 5);
    marker.features.push(
                    new OpenLayers.Feature.Vector(
                        new OpenLayers.Geometry.Point(coords[0], coords[1])
                    )
                );
  }
</script>

I'm grateful for any suggestions.

Sean