Ext store.reload()之后，无法获取最新的数据？解决思路

//定义一个USERstore
var fields = ["user_no","user_id","user_name","lpwd","shop_no","shop_name","isadmin","lltime","available"];
    var USERstore = new Ext.data.GroupingStore({
        proxy:new Ext.data.HttpProxy(
        {
            url:"sys_user_info.aspx",
            method:"POST"
        }),
        reader:new Ext.data.JsonReader(
        {
            fields:fields,
            root:"data",
            id:"user_no",
            totalProperty:"totalCount"
        }),
        sortInfo:{field:'user_no',direction: "ASC"}
    });
    //加载时参数
    USERstore.load({params:{start:0,limit:pageSize}});

//增加数据页面提交处理
EditUserInfofp.form.submit({
url:"user_edit.aspx,
params:{dp_datas:jsonData},
method:"POST",
success:function(form,action)
{
Ext.MessageBox.show({
title: '恭喜',
msg:'信息保存成功!',
icon:Ext.MessageBox.INFO
});
//刷新数据集
USERstore.reload();
[b][color=#FF0000][size=12px]此处调试过USERstore，的确从后台已经重新加载，数据是最新的，可是引用USERstore，却发现还是之前的数据，而并非最新的数据，why？？？[/size][/color][/b]EditUserInfoWin.hide();
},
failure:function(form,action)
{
Ext.MessageBox.show({
title: '提示',
msg:'保存信息失败!',
icon:Ext.MessageBox.ERROR
});
}
});