jQuery Grid Plugin - jqGrid

I do not want to sort any of the columns in my jqGrid.  I have used 'sortable: false' on all columns in the column model, but the columns are still allowing sorting.  Below is my code to set up the grid:

$(document).ready(function () {

   $.ajax({

      type: "GET",

      url:  "BethTest?action=fetchData",

      dataType: "json",

      success:  function(result)

      {

         colN = result.names;

         colD = result.data;

         colM = result.model;

         jQuery("#list2").jqGrid({

            datatype: "jsonstring",

            colNames: colN,

            colModel: colM,

            datastr: colD,

            pager: "#pager2",

            rowNum: 10,

            rowList: [10,20,30],

            gridview: true,

            autoencode: true,

            loadonce: true,

            caption: "My List"

            })

         }

      })

})

}

The colModel looks like: {name: "name here", sortable: false, width: 100} this is the format for each row.