jqgrid columns not sorting when clicked
===

I have the following block of code: 

    $("#searchlist").jqGrid({
				    url:'./searchlibrary',
				    datatype: 'json',
				    mtype: 'POST',
				    postData: {type: function(){return $('select[name="searchtype"]').val();},
				    	criteria: function(){return getSearchData();}
				    },
				    colNames:['Resource Name','Unit', 'Topic','Document Type','Content Type','Select'],
				    colModel :[ 
				      {name:'resourceName', index:'resourceName', width:380, align:'left'}, 
				      {name:'unit', index:'unitID', width:40, align:'center',sortable:true}, 
				      {name:'topic', index:'topicID', width:220, align:'center',sortable:true}, 
				      {name:'docType', index:'docTypeID', width:97, align:'center',sortable:true}, 
				      {name:'contentType', index:'contentTypeID', width:97, align:'center',sortable:true},
				      {name: 'select', index:'resourceID', width:55, align: "center", sortable: false, editable: true, edittype: "checkbox", editoptions: { value:"Yes:No", defaultValue:"No" }, formatter:"checkbox",formatoptions: {disabled : false}}
				    ],
				    rowNum:20,
				    sortname: 'resourceName',
				    sortorder: 'asc',
				    viewrecords: true,
				    gridview: true,
				    width:878,
				    height:251,
				    loadComplete: function(data){
				    	initCheckboxes();
				    	$('input[type="checkbox"]').click(function(ev){
			  				initCheckboxes();
			  			});
				    }
				 });

The data loads just fine, however when I click the various column headers they don't sort. The loading box shows up briefly over the data, but the columns never actually re-sort. The only column that the sort works on is the very first column. Any help would be greatly appreciated.