title: Isolated Storage - strange error with Exception
body: <p>I try save picture in <code>IsolatedStorage</code> on my Device. I turn OFF the internet and tap the button in my application. At the first time, exception is appears correctly:
  "The remote server returned an error:
  NotFound."</p>
  
  <p>the next step: I turn ON the internet and tap the button - the image is saved on my phone.
  Everything is ok.</p>
  
  <p>And now is the most important thing: when I again turn off the internet i will never see again this exception (if i want see I must uninstall, and install app again)</p>
  
  <p>Why?</p>
  
  <p>p.s: sorry for my english</p>
  
  <pre><code>public void update()
  {
      WebClient client = new WebClient();
      client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
      client.OpenReadAsync(new Uri(@"http://www.myurl.com/" + path + "/" + number.ToString() + ".jpg"), client);
  }
  
  void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
  {
      try
      {
          var resInfo = new StreamResourceInfo(e.Result, null);
          var reader = new StreamReader(resInfo.Stream);
          byte[] contents;
  
          using (BinaryReader bReader = new BinaryReader(reader.BaseStream))
          {
              contents = bReader.ReadBytes((int)reader.BaseStream.Length);
          }
  
          if (!MyStore.DirectoryExists(path))
              MyStore.CreateDirectory(path);
  
          IsolatedStorageFileStream stream = MyStore.CreateFile(path +"/"+ number.ToString() + ".jpg");
          stream.Write(contents, 0, contents.Length);
          stream.Close();
      }
  
      catch (Exception ex)
      {
          MessageBox.Show(ex.Message);
      }
  
  }
  </code></pre>