Problem with migration to v1.9.4

We used v1.8.1 for our old project. Now we are trying to migrate to 1.9.4. At this moment, we use twitter bootstrap 2.1, jquery 1.8.2 with datatable 1.9.2 but we still get errors.

Here is our code
HTML

<table id="tblUser" class="table-display">
    <thead>
    <tr>
        <th>User name</th>
        <th>Source</th>
        <th>DN(s)</th>
    </tr>
    </thead>
    <tbody>
    
    </tbody>
    <tfoot>
    </tfoot>
</table>

Javascript

<script>
$(document).ready(function() {
		$("#tblUser").dataTable({
			"bProcessing": true,
			"bSort" : false,
	                "bServerSide": true,
         	        "sAjaxSource": "${ctx}/jsp/struts/resource/fseuser/fseuser.do?method=generalUserList",
	                "aoColumnDefs": [
	                         {
	                           "fnRender": function ( oObj ) {
	                             return "test";
	                           },
	                           "bUseRendered": false,
	                           "aTargets": [ 0 ]
	                         },
	                         {
                                  "fnRender": function ( oObj ) {
                                     return "test";
                                   },
                                   "bUseRendered": false,
                                   "aTargets": [ 1 ]
                                 },
                                 {
                                  "fnRender": function ( oObj ) {
                                     return "test";
                                  },
                                  "bUseRendered": false,
                                  "aTargets": [ 2 ]
                                 }
	                   ]
		});
	});
</script>

And this is our responded data:

{"sEcho":0,"iTotalRecords":"10","iTotalDisplayRecords":"27","aaData":[{"acpId":"","acps":[],"certificate":[],"createDate":"2012-10-24 11:33:49","createUserKey":"","desc":"","descHtml":"","displayName":"cly4" .... }]}

Datatable successfully retrieves data from server, but it cannot parse data and render on page. I have no error on firebug. Is there anyone having the same issue?