c# - WinXP で HttpWebRequest Cookie が機能しない

Question

これを WinXP で実行すると問題が発生し (Windows 8 および Windows 7 では問題なく実行されます)、どこに問題があるのか​​わかりません。

管理ページにログインする必要がありますが、それでもパスワードを求められます。（ユーザー名が表示されます）。だから私はクッキーに何かがあると思います。

私は.netフレームワーク4を使用しています

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Net;
using System.IO;

namespace ConsoleApplication1
{
    class dataDumper
    {

        CookieCollection cookie_Collection = new CookieCollection();
        CookieContainer cookie_Container = new CookieContainer();

        static string username = "MY_Username";
        static string password = "MY_Password";
        static string domain = "https://www.infojobs.it";

        string linklogin = domain + "/employer-login-run.xhtml";
        string linkmanagement = domain + "/employer/manage/offers/management-view.xhtml";
        string postData = String.Format("email=" + username + "&password=" + password + "&j_clientId=empleo_it&submit=Entra");

        public void Start()
        {
            webPageHome();
            webPageLogin();
            webPageManagement();
        }

        #region PageDumper
        private void webPageHome()
        {
            HttpWebRequest getRequest = (HttpWebRequest)WebRequest.Create(domain);
            getRequest.CookieContainer = cookie_Container;
            getRequest.CookieContainer.Add(cookie_Collection);

            HttpWebResponse getResponse = (HttpWebResponse)getRequest.GetResponse();
            cookie_Collection = getResponse.Cookies;

            using (StreamReader sr = new StreamReader(getResponse.GetResponseStream(), Encoding.Default, true))
            {
                //read the login page
                string loginsourceCode = sr.ReadToEnd();
                File.WriteAllText("home.txt", System.Web.HttpUtility.HtmlDecode(loginsourceCode));
            }
        }

        private void webPageLogin()
        {
            HttpWebRequest getRequest = webRequest(linklogin, postData);
            getRequest.CookieContainer.Add(cookie_Collection);

            HttpWebResponse getResponse = (HttpWebResponse)getRequest.GetResponse();
            cookie_Collection = getResponse.Cookies;

            using (StreamReader sr = new StreamReader(getResponse.GetResponseStream(), Encoding.Default, true))
            {
                //read the login page
                string loginsourceCode = sr.ReadToEnd();
                File.WriteAllText("login.txt", System.Web.HttpUtility.HtmlDecode(loginsourceCode));
            }
        }

        private void webPageManagement()
        {
            HttpWebRequest getRequest = webRequest(linkmanagement, postData);
            getRequest.CookieContainer.Add(cookie_Collection);

            HttpWebResponse getResponse = (HttpWebResponse)getRequest.GetResponse();
            cookie_Collection = getResponse.Cookies;

            using (StreamReader sr = new StreamReader(getResponse.GetResponseStream(), Encoding.Default, true))
            {
                //read the management page
                string managementsourceCode = sr.ReadToEnd();
                //parse the result
                File.WriteAllText("management.txt", System.Web.HttpUtility.HtmlDecode(managementsourceCode));
            }
        }
        #endregion


        private HttpWebRequest webRequest(string getUrl, string postData = null)
        {
            HttpWebRequest getRequest = (HttpWebRequest)WebRequest.Create(getUrl);
            getRequest.CookieContainer = cookie_Container;

            getRequest.Method = WebRequestMethods.Http.Post;
            getRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.121 Safari/535.2";
            getRequest.AllowWriteStreamBuffering = true;
            getRequest.ProtocolVersion = HttpVersion.Version11;
            getRequest.AllowAutoRedirect = true;
            getRequest.ContentType = "application/x-www-form-urlencoded";

            if (postData != null)
            {
                byte[] byteArray = Encoding.ASCII.GetBytes(postData);
                getRequest.ContentLength = byteArray.Length;
                Stream newStream = getRequest.GetRequestStream(); //open connection
                newStream.Write(byteArray, 0, byteArray.Length); // Send the data.
                newStream.Close();
            }
            else
            {
                getRequest.GetRequestStream();
            }

            return getRequest;
        }

    }

}