HTTP Post XML document - server receives only first line

I have C# application that sends an XML document to a server via HTTPS Post. The problem is that the server receives only the first line <?xml version="1.0" encoding="UTF-8"?>. Here is a truncated version of my code (important parts only). What could be causing this problem? Is there modify in my code?

SSL connectivity to the server 开发者_开发问答has been assured, and the message I recevie in return is "document type not accepted".

thanks!

 StreamWriter loPostData = null;
 HttpWebRequest loHttp = null;
 HttpWebResponse loWebResponse = null;
 byte[] buffer;

 String uri = ConfigurationSettings.AppSettings["URL"];

 loHttp = (HttpWebRequest)WebRequest.Create(uri);
 buffer = Encoding.ASCII.GetBytes(payload);

 //Request Header
 loHttp.ProtocolVersion = HttpVersion.Version11;
 loHttp.KeepAlive = true;
 loHttp.Accept = "text/xml;charset=\"utf-8\"";
 loHttp.Method = WebRequestMethods.Http.Post;
 loHttp.ContentType = "text/xml;charset=\"utf-8\"";
 loHttp.ContentLength = buffer.Length;
 loHttp.SendChunked = true;
 loHttp.TransferEncoding = "7bit";
 loHttp.AllowWriteStreamBuffering = true;

 ServicePointManager.ServerCertificateValidationCallback += delegate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
   {
       return true; // **** Always accept return
   };

   X509Certificate x509_1 = new X509Certificate(ConfigurationSettings.AppSettings["OPEN_INVOICE_CERTIFICATE"]);
   loHttp.ClientCertificates.Add(x509_1);

    //Send data
   loPostData = loHttp.GetRequestStream();
   loPostData.Write(buffer, 0, buffer.Length);
   loPostData.Close();

    //Get a response
    loWebResponse = (HttpWebResponse)loHttp.GetResponse();
    StreamReader responsestream = new StreamReader(loWebResponse.GetResponseStream());
    String rsp = responsestream.ReadToEnd();

    responsestream.Close();

Based on the error message you are getting, are you sure that the page you are calling REALLY wants the content type to be text/xml? It might be that you need to post it like a standard webrequest instead of posting an HTML file directly by content type.

It turns out the lines
loHttp.SendChunked = true;
loHttp.TransferEncoding = "7bit";
weren't needed.