I have found this workaround. Please test and see if it works for you.Replace your : dojo.connect(map,"onClick",function(evt)with the code given below:dojo.connect(map,"onClick",function(evt){
var query = new esri.tasks.Query();
query.geometry = pointToExtent(map,evt.mapPoint,10);
var deferred = featureLayer.selectFeatures(query,esri.layers.FeatureLayer.SELECTION_NEW);
map.infoWindow.setFeatures([deferred]);
map.infoWindow.show(evt.mapPoint);
map.infoWindow.resize(200,100);
map.centerAt(evt.mapPoint);
});
I am not sure thought if this was your problem! But there is no harm in trying:)