XListView下拉刷新的问题

[请叫我周周周]

报错：

java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. Make sure your adapter calls notifyDataSetChanged() when its content changes. [in ListView(2131034293, class com.gaokao.ppst.utils.XListView) with Adapter(class android.widget.HeaderViewListAdapter)

onRefresh()的代码：

@Override
public void onRefresh() {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
URL = "http://10.230.17.157:8080/yygk/SetNewsList";
new NewsListLoadMore().execute(URL);//这里执行异步操作的
onLoad();
}
}, 2000);
}

这里是AsyncTask中onPostExecute中的代码，在这里更新adapter

if (mAdapter == null) {
mAdapter = new TabNewsListViewAdapter(mContext, result);
mNewsListView.setAdapter(mAdapter);
mAdapter.notifyDataSetChanged();
} else {
mAdapter.onDateChange(result);
mAdapter.notifyDataSetChanged();
}

求大神帮忙看看那里出了问题
还有一个问题是，上面我的更新时间是定的2秒，怎么异步加载时间呢？

[h1324694009]

线程里面不可以更新UI中的view