Trouble with HTTP cookie

Hi, the code below work fine when in a .net 1.1 app pool, but as soon as I put it in a .net2 app pool it fails to redirect to the default home page even though the user is authenticated

public static bool AuthenticateUser(string userId, string password, bool persistCookie)
        {
            bool flag = false;
            if (BoostApplication.ValidateUser(userId, password))
            {
                DateTime now = DateTime.Now;
                DateTime expiration = now;
                if (persistCookie)
                {
                    expiration = expiration.AddYears(1);
                }
                FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1, userId, now, expiration, persistCookie, userId);
                string str = FormsAuthentication.Encrypt(ticket);

                HttpContext.Current.Response.Cookies.Add(new HttpCookie(FormsAuthentication.FormsCookieName, str));
                
                //HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, str);

                if (persistCookie)
                {
                    //cookie.Expires = expiration;
                }
                //HttpContext.Current.Response.Cookies.Add(cookie);
                
                
                BoostApplication.SetUserAndLanguage(userId, BoostApplication.CurrentLanguage);
                if (AuthenticationTicket(HttpContext.Current) != null)
                {
                    flag = true;
                }
            }
            return flag;
        }

  void btnLogin_Click(Object sender, EventArgs e)
  {
    if (Campus.CampusApplication.AuthenticateUser(txtUserId.Text, txtPassword.Text))
    {
	  Response.Redirect("~/home.aspx", false);
	  }
    else
    {
      pnlError.Visible = true;
	  Response.Write("h");
    }
  }

The commented out lines are the what are used when running in a .net 1.1 app pool, so I would uncomment them when running in a .net 1.1 app pool.

Thanks