jQuery Grid Plugin - jqGrid

Not sure where to put this, but this room seem the best to me. 😀

Anyway I got this "g.headers[c] is undefined" error when I try to load json data into jqgrid.

I am using jqgrid 3.6.4 on jquery 1.3.2. My jqgrid setting is like this :

jQuery(document).ready(function(){
    jQuery("#list").jqGrid({  
        url:'getCountiresIso',  
        datatype: 'json',  
        mtype: 'GET',  
        colNames:['ISO','Name', 'Printable Name','ISO3','Numeric Code'],  
        colModel :[ {name:'iso', index:'iso', width:55},  
                    {name:'name', index:'name', width:90},  
                    {name:'printable_name', index:'printable_name', width:150, align:'right'},  
                    {name:'iso3', index:'iso3', width:80, align:'right'},  
                    {name:'numcode', index:'numcode', widthwidth:80, align:'right'}],
        pager: jQuery('#pager'),  
        rowNum:10,  
        rowList:[10,20,30],  
        sortname: 'id',  
        sortorder: "desc",  
        viewrecords: true,  
        imgpath: 'themes/basic/images',  
        caption: 'My first grid' });
});
jQuery("#list").jqGrid('navGrid','#pager',{edit:false,add:false,del:false});

surely I have these

<table id="list" class="scroll"></table>  
<div id="pager" class="scroll" style="text-align:center;"></div>

The json is

{"page":"1","total":24,"records":239,"rows":[{"id":"1","cell":["1","AF","AFGHANISTAN","Afghanistan","AFG"
,"4"]},{"id":"2","cell":["2","AL","ALBANIA","Albania","ALB","8"]},{"id":"3","cell":["3","DZ","ALGERIA"
,"Algeria","DZA","12"]},{"id":"4","cell":["4","AS","AMERICAN SAMOA","American Samoa","ASM","16"]},{"id"
:"5","cell":["5","AD","ANDORRA","Andorra","AND","20"]},{"id":"6","cell":["6","AO","ANGOLA","Angola","AGO"
,"24"]},{"id":"7","cell":["7","AI","ANGUILLA","Anguilla","AIA","660"]},{"id":"8","cell":["8","AQ","ANTARCTICA"
,"Antarctica",null,null]},{"id":"9","cell":["9","AG","ANTIGUA AND BARBUDA","Antigua and Barbuda","ATG"
,"28"]},{"id":"10","cell":["10","AR","ARGENTINA","Argentina","ARG","32"]}]}

Is there anyone can point me where have I gone wrong? 
FYI, if I only set one column for both header and data I didn't find the error.

thanks in advance