title: jqGrid not sorting after triggering reload
body: <p>I have a grid with the following definition. Everything is working fine with the grid as is.</p>
  
  <pre><code>$("#grid").jqGrid({
      url:'report_data.php',
      datatype: 'json',
      mtype: 'POST',
      colNames:['Type','Term','Number','Visits','Calls','Unique','Avg. Duration',
                'Conversion Rate'],
      colModel :[{"index":"keyword_type","name":"Type","width":90},
                 {"index":"keyword","name":"Term","width":170},
                 {"index":"phone_number","name":"Number","width":100},
                 {"index":"visits","name":"Visits","width":80},
                 {"index":"calls","name":"Calls","width":70},
                 {"index":"unique_calls","name":"Unique","width":70},
                 {"index":"avg_duration","name":"Avg. Duration"},
                 {"index":"conversion_rate","name":"Conversion Rate","width":80}],
      rowNum:100,
      rowList:[25,50,100,200,500],
      sortname: 'keyword_type',
      sortorder: 'desc',
      viewrecords: true,
      height: '470px',
      width: 'auto',
      loadui: 'block',
      postData: {"keyword_set":"140","display_type":"direct"}
  });
  </code></pre>
  
  <p>There are links on the page to filter the grid. When the user clicks a link I set some grid params and reload the grid using:</p>
  
  <pre><code>var param_string = "filter=keyword&amp;type=ppc";
  $('#grid').setGridParam({url:'report_data.php',
                           postData:param_string}).trigger("reloadGrid"); 
  </code></pre>
  
  <p>The grid reloads fine with the new data, however, the columns are no longer sortable. I can see the data getting sent to the server but it no longer includes the 'sidx' or 'sord' parameters. Sorting worked fine before triggering the reload.</p>
  
  <p>Any ideas on how to get the sort parameters passed again after reloading the grid?</p>
  
  <p>Thanks,
  Dan</p>