WebRequest.BeginGetResponse Problems...

So I am trying to implement a Async HttpWebRequest/HttpWebResponse call on a Background Thread apart from the Main UI Thread.

Although everytime, the Response is "called-back", for some reason it uses the UI thread, is there anyway to not let this happen.

Basically, when I run the Async calls, the actual methods are free from the UI, except the actual calling of the delegate methods, which cause my mouse pointer to show the "loading/progress" cursor...

Ex.

Code:

---

private ManualResetEvent allDone = new ManualResetEvent(false);

private void button1_Click(object bsender, EventArgs bve)
{
        Thread t = new Thread(new ThreadStart(delegate()
        {
                string url = "http://example/"
                HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
                req.Method = "POST";
                req.ContentType = "multipart/form-data; boundary=" + Config.REQUEST_BOUNDARY;

                req.BeginGetRequestStream(GetRequestStreamCallback, req);

                allDone.WaitOne();

                Console.WriteLine("Request/Response Callback is Done...");

        }));
        t.IsBackground = true;
        t.Start();
}

private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
{
        //Add data to request stream...

        //This line seems to be the culprit of making my UI thread hang for a second...
        request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);
}

private void GetResponseCallback(IAsyncResult asynchronousResult)
{
        HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;

        HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
        Stream streamResponse = response.GetResponseStream();
        StreamReader streamRead = new StreamReader(streamResponse);
       
        string responseString = streamRead.ReadToEnd();
       
        Console.WriteLine("Response Callback: " + responseString);
        streamResponse.Close();
        streamRead.Close();

        response.Close();
        allDone.Set();
}

---

Moved from c# to asp.net (but with a 1 month link in c# forum) as I do believe here you should find a better help

by the way, even if this is coded in VB, the concept of a secondary thread thhat should get the callback seems what you're looking for:
http://msdn.microsoft.com/en-us/magazine/cc188732.aspx

All I am wondering is why does the WebResponse Callback always use the UI thread...

And is there a way to stop this from happening?