<script type="text/javascript" src="http://servicesbeta.esri.com/jsapi/arcgis/2.8"></script>
<script type="text/javascript" src="http://servicesbeta.esri.com/jsapi/arcgis/2.9"></script>
<script type="text/javascript" src="http://servicesbeta.esri.com/jsapi/arcgis/3.0"></script>
The move from 1.6 to 1.7 is noteworthy...try using the AMD syntax as shown in the jsfiddle above or show me a jsfiddle which doesn't work and maybe I can fix it:
require ( ["esri/map", "esri/layers/wms"], function () {
// your code
});