title: dojo1.7 Enhancedgrid is not refreshed when new store is assigned in IE
body: <p><br> I am working on dojo1.7. I have an EnhancedGrid which I need to refresh with latest data.</p>
  
  <blockquote>
    <blockquote>
      <p>var gridStore = new dojo.data.ItemFileWriteStore({
                              url:'',
                              data:result,
                              urlPreventCache: false
                          });</p>
    </blockquote>
  </blockquote>
  
  <pre><code>                grid.store=gridStore;
                  grid._refresh();   
  </code></pre>
  
  <p>I am fetching some data in required format </p>
  
  <p>var result = {
          "identifier": "id",<br>
      "items": [] //jsonobject
      };</p>
  
  <p>The above code works fine on firefox however on IE I am getting an error 'null is null or not an object'. I am not sure what is going wrong in IE. Is there any other way of changing the store in dojo1.7? <br>Thanks in advance!</p>