load events not working properly in OpenLayers.Tile.Image.IFrame, r=fvanderbiest (closes #2406)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@10082 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

tests/Tile/Image/IFrame.html

@@ -106,7 +106,8 @@
         layer = new OpenLayers.Layer.WMS.Post(name, wmsUrl, {layers: 'basic'}); 
         map.addLayer(layer);  
         var tile = new OpenLayers.Tile.Image.IFrame(layer, position, bounds, url, size);
-        var imgDiv    = tile.createImgDiv();
+        tile.renderTile();
+        var imgDiv = tile.imgDiv;
         var iFrame    = imgDiv.firstChild;
         var eventPane = imgDiv.childNodes[1];