ArcGISDynamicMapServiceLayer gets reprojected on the fly. We do not have to take care for the projection of the dynamic map service.Take a look at this simple applicaiton which adds a basemap and adds ArcGISDynamicMapServiceLayer on top of it.Spatial Refrence:ArcGISTiledMapServiceLayer : 102100ArcGISDynamicMapServiceLayer : 4269Still both shows up on the map.<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=7,IE=9" />
<!--The viewport meta tag is used to improve the presentation and behavior of the samples
on iOS devices-->
<meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no"/>
<title>Map Zoom Rectangle Symbol</title>
<link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/dojo/dijit/themes/claro/claro.css">
<link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/esri/css/esri.css" />
<script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=3.2"></script>
<script type="text/javascript">
dojo.require("esri.map");
function init() {
//configure map zoom rectangle fill by setting style by calling esri.symbol.SimpleFillSymbol.toJson()
var initExtent = new esri.geometry.Extent({"xmin":-13814922,"ymin":332653,"xmax":6222585,"ymax":10351408,"spatialReference":{"wkid":102100}});
var map = new esri.Map("map",{extent:initExtent});
var basemap = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer");
map.addLayer(basemap);
var operationalLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer");
map.addLayer(operationalLayer);
}
dojo.addOnLoad(init);
</script>
</head>
<body class="claro">
Configure map zoom rectangle symbol
<div id="map" style="width:1024px; height:512px; border:1px solid #000;"></div>
</body>
</html>
Copy this code and replace the URL for ArcGISDynamicMapServiceLayer with your URL and see if it shows up on the map.Let me know.-Shreyas