SSL curl connection not working

Hi,
I'm trying this SSL curl connection without success:

<?php
header('Content-Type: text/xml');

$url=3Durlencode("https://www.one-server.com/one-cgi.cgi");
$request=3D"<request><plaintext>1111222233334444</plaintext></request>";

$ch =3D curl_init();
$res=3D curl_setopt ($ch, CURLOPT_URL,$url);

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER , true);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST , true);
curl_setopt($ch, CURLOPT_PORT, 443);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $request);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

$response =3D curl_exec ($ch);

curl_close ($ch);

print_r($response);
?>
The error I get is :

"Error de lectura XML: no se encuentra elemento
Ubicaci=F3n: http://my_server.com/index.php
N=FAmero de l=EDnea 1, columna 1:"

Any ideas ???