jQuery.jqGrid()的分页显示出现问题，请大神帮忙解决一下？！

页面的代码：
$(document).ready(function(){
jQuery("#user").jqGrid({
url:'${ctx}/registerAction!userList.action',
datatype: 'json',
mtype: 'POST',
colNames:['序号','登录名','密码','登录名','密码'],
colModel:[
{name:'userId',index:'userId',width:100, align:"center",hidden:true},
{name:'userName',index:'userName',width:100, align:"center"},
{name:'passWord',index:'passWord',width:100, align:"center"},
{name:'userName',index:'userName',width:100, align:"center"},
{name:'passWord',index:'passWord',width:100, align:"center"}
],
pager: '#pager',
sortable: true,
rowNum:2,
jsonReader: {

root: "rows",

repeatitems : false
},
rowList:[2,5,9],
prmNames:{rows:"page.pageSize",page:"page.pageNumber",total:"page.totalPages"},
sortname: 'userId',
sortorder: 'asc',
height: '100%',
scrollrows: true,
viewrecords: true
});
})

action层代码：
public String userList(){
pageUser = registerService.userList();
ObjectMapper mapper = new ObjectMapper();
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
mapper.getSerializationConfig().setDateFormat(dateFormat);

    Map mapResult = new HashMap();
    mapResult.put("pageUser", Integer.valueOf(pageUser.getPageNumber()));
    mapResult.put("total", Integer.valueOf(pageUser.getTotalPages()));
    mapResult.put("records", Integer.valueOf(pageUser.getTotalCount()));
    mapResult.put("rows", pageUser.getResult());

    String jsonResult;
    try {
        jsonResult = mapper.writeValueAsString(mapResult);
        System.out.println("jsonResult----------"+jsonResult);
        Struts2Utils.renderText(jsonResult);
    } catch (JsonGenerationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (JsonMappingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return null;
}

引用的js：
<link href="js/jquery/jqGrid/css/jquery-ui-1.8.1.custom.css" rel="stylesheet" type="text/css" />
<link href="js/jquery/jqGrid/css/ui.jqgrid.css" rel="stylesheet" type="text/css" />
<script src="js/jquery/jquery-1.8.3.js" type="text/javascript"></script>
<script src="js/jquery/jqGrid/js/jquery-ui-1.8.1.custom.min.js" type="text/javascript"></script>
<script src="js/jquery/jqGrid/js/grid.locale-en.js" type="text/javascript"></script>
<script src="js/jquery/jqGrid/js/jquery.jqGrid.min.js" type="text/javascript"></script>
<script src="js/jquery/jqGrid/js/grid.subgrid.js" type="text/javascript"></script>

json：
jsonResult----------{"total":0,"rows":[{"userName":"1111","userId":21,"passWord":"1111"},{"userName":"qqq","userId":6,"passWord":"qqq"},{"userName":"sangqiang","userId":1,"passWord":"123456"}],"records":0,"pageUser":1}