easyui中datagrid绑定返回的json字符串在IE中正常FF显示不了数据

easyui中datagrid绑定返回的json字符串（通过url返回的）在IE中正常FF显示不了数据，
$(function(){
$('#test').datagrid({
title:'My Title',
iconCls:'icon-save',
              fitColumns:true, 
nowrap: false,
striped: true,
collapsible:true,
url:'WebForm1.aspx',
idField:'orderID',
frozenColumns:[[
               {field:'选中框',checkbox:true},
                {title:'orderID',field:'orderID',width:80,sortable:true},
                {title:'pID',field:'pID',width:80,sortable:true},
                {title:'pUnitPrice',field:'pUnitPrice',width:80,sortable:true},
                {title:'pCount',field:'pCount',width:80,sortable:true},
                {title:'pName',field:'pName',width:80,sortable:true},
                {title:'buyTime',field:'buyTime',width:80,sortable:true},
                {title:'pDiscount',field:'pDiscount',width:80,sortable:true},
                {title:'uID',field:'uID',width:80,sortable:true},
                
]],