title: ArrayCollection removing sort
body: <p>After applying a numeric sort to my dataprovider(Array Collection), I can not reorder the items via a tilelist. Do I need to remove the sort from the arrayCollection. If so, is it just a case of setting collection.sort = null ?</p>
  
  <pre><code>var sortField:SortField=new SortField();
  sortField.name="order";
  sortField.numeric=true;
  var sort:Sort=new Sort();
  sort.fields=[sortField];
  </code></pre>