Cannot Send HTTP Request in Windows Service

Below highlighted is where code gets error. I include some other code as it may be useful. Not sure what is happening as the code worked before for many months and now all of a sudden it stopped working. It seems that it is not able to send the HTTP request. The windows service is running on a Windows 2003 server.

I tried running on a different proxy and without one on the server and still get the same error.

 

HttpWebRequest webRequestExAnte   = CreateWebRequest(_url, _action);

….
                using (WebResponse webResponse = webRequestExAnte.EndGetResponse(asyncResultExAnte))*****errors out saying underlying connection is closed: An unexpected error occurred on a send
                {
                    using (StreamReader rd = new StreamReader(webResponse.GetResponseStream()))
                    {
                        soapResultExAnte = rd.ReadToEnd();
                    }
                }


        private static HttpWebRequest CreateWebRequest(string url, string action)
        {
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
            webRequest.Headers.Add("SOAPAction", action);
            webRequest.ContentType = "text/xml";
            webRequest.Accept = "text/xml";
            webRequest.Method = "POST";
            webRequest.ProtocolVersion = HttpVersion.Version11;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
            ServicePointManager.DefaultConnectionLimit = 200;


            //create the proxy
            ICredentials credentials = new NetworkCredential("X Datafeed", "");
            IWebProxy webProxy = new WebProxy(ConfigurationManager.AppSettings.Get("ProxyAddress") + ":" + ConfigurationManager.AppSettings.Get("ProxyPort"), true);

            webProxy.Credentials = credentials;
            webRequest.Proxy = webProxy;

            //add the certificate
            try
            {
                X509Certificate2 col = new X509Certificate2(ConfigurationManager.AppSettings.Get("Path"), ConfigurationManager.AppSettings.Get("XFeedPwd"), X509KeyStorageFlags.MachineKeySet);

                webRequest.ClientCertificates.Add(col);

            }

            catch (Exception ex)

            {

                EventLog eventlog = new EventLog();
                eventlog.Source = "XFeed";
                eventlog.Log = "XLog";
                eventlog.WriteEntry("Exception encountered in CreateWebRequest: " + ex.Message.ToString(), EventLogEntryType.Warning);

            }

          
            //webRequest.KeepAlive = true;  -- tried this here didn't work
            return webRequest;

        }

Select allOpen in new window

 
It looks to be getting an error where the *** are above when I step through the code. Error message is: The underlying connection was closed: An unexpected error occurred on a send.

Any yes I looked at this article http://support.microsoft.com/kb/915599/en-us but still could not resolve.