silverLight调试出错

silverLight web中对应的TestPage可以正常打开

但是把应用程序设为启动项目进行调试时 Client对应的BaseAddress 是：file:///E:/VS2010Test/SL/LoginTest/LoginTest/Bin/Debug/LoginTest

调用client_DownloadStringCompleted时
XmlReader reader = XmlReader.Create(new StringReader(e.Result));  //出错
“操作过程中出现异常，结果无效。有关异常的详细信息，请查看 InnerException”

具体代码：
private void Download_Click(object sender, RoutedEventArgs e)
        {
            Uri uri = new Uri(HtmlPage.Document.DocumentUri,"Images.xml");
            WebClient client = new WebClient();
            string baseurl = client.BaseAddress;  //file:///E:/VS2010Test/SL/LoginTest/LoginTest/Bin/Debug/LoginTest
            client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
            client.DownloadStringAsync(uri);
        }

        private void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
        {
            //使用Linq To XML处理数据
            XmlReader reader = XmlReader.Create(new StringReader(e.Result));  //出错
            XDocument doc = XDocument.Load(reader);
            var list = (from image in doc.Descendants("image")
                        select new Uri(HtmlPage.Document.DocumentUri, image.Attribute("uri").Value)).ToList();
            this.stackPanel1.Children.Clear();
            foreach (var u in list)
            {
                //动态加载
                Image image = new Image();
                image.Width = 50;
                image.Height = 50;
                image.Source = new BitmapImage(u);
                image.Margin = new Thickness(10, 10, 10, 10);
                this.stackPanel1.Children.Add(image);
            }
        }
请问如何修改？ silverLight 调试 --------------------编程问答-------------------- 有关异常的详细信息，请查看 InnerException --------------------编程问答-------------------- 请问怎么解决的呢？

补充：.NET技术 ,  ASP.NET