c# login to IBM CLM exception

I try to login to IBM CLM server using some c# code from

http://blog.boriskuschel.com/2012/02/c-with-visual-studio-and-rational-team.html?showComment=1399373273027#c2233627067206926337

I am stuck at the part where the code throws an exception at the last instruction:

                if ((header != null) && header.Equals("authrequired"))
                {
                    documentResponse.GetResponseStream().Flush();
                    documentResponse.Close();
                    // The server requires an authentication: Create the login form

                    HttpWebRequest formPost = (HttpWebRequest)WebRequest.Create(serverURI + "/j_security_check");
                    formPost.Method = "POST";
                    formPost.Timeout = 30000;
                    formPost.CookieContainer = request.CookieContainer;
                    formPost.ContentType = "application/x-www-form-urlencoded";
                    String output = "j_username=" + login + "&j_password=" + password;
                    Byte[] outputBuffer = Encoding.UTF8.GetBytes(output);
                    formPost.ContentLength = outputBuffer.Length;
                    Stream stream = formPost.GetRequestStream();
                    stream.Write(outputBuffer, 0, outputBuffer.Length);
                    stream.Close();

                    // Step (2): The client submits the login form
                    if (DEBUG) Console.WriteLine(">> POST " + formPost.RequestUri);
                    HttpWebResponse formResponse = (HttpWebResponse)formPost.GetResponse();
..
}
Error: The remote server returned an error: (408) Request Timeout.

I wonder whats wrong ...
Best regards
Can you please help ?