multiple curl and web service

Hi, I am having this problem, I am retrieving some data from a MySQL DB, and using it to post a cURL, what I am calling is a web service, and I have 3 options to do it: SOAP, GET and POST, I am not very familiar with SOAP, so I am using POST, in response I get a XML on each call to the web service. If I call only one curl and web service each time, then everything works just perfect, but if I try to make multiple calls then I get weird results, I get some responses OK (an XML), but others are empty responses. The first three responses are always empty, I don't get any errors, instead only those empty responses (no XML). Ok, I'm posting the code right here: $sql_aero = "SELECT

                        code
                    FROM
                        airports
                    ORDER BY
                        id ASC
                        limit 0, 10";

    $result_aero = mysql_query($sql_aero);
    $num_results_aero = mysql_num_rows($result_aero);
    if (!empty($num_results_aero)) {
        $i = 0;
        $mh = curl_multi_init();
        while($row_aero = mysql_fetch_array($result_aero)) {
            $aero = $row_aero["code"];
            $ws = "www.webservicex.com/airport.asmx/getAirportInformationByAirportCode";
            $post = "airportCode=$aero";
            print "$i = $aero, $post<br>";
            $conn[$i] = curl_init($ws);
            curl_setopt($conn[$i], CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($conn[$i], CURLOPT_POSTFIELDS, $post);
            curl_multi_add_handle ($mh, $conn[$i]);
            $i++;
        }
    }

    do {
        $mrc = curl_multi_exec($mh, $active);
    } while ($mrc == CURLM_CALL_MULTI_PERFORM);

    for ($j=0; $j<$i; $j++) {
        if (($err = curl_error($conn[$j])) == '') {
            $res[$j] = curl_multi_getcontent($conn[$j]);
            print "$j<br>$newstr[$j]";
        }
        else {
            print "Curl error on handle $j: $err\n";
        }
        curl_multi_remove_handle($mh, $conn[$j]);
        curl_close($conn[$j]);
    }
    curl_multi_close($mh);

As you won't have the DB, if want to try the code, use this array with the proper change to the code: $airports = ['LAX', 'ATL', 'JFK', 'SAN', 'CDG', 'MAD', 'BCN', 'GDL', 'TIJ', 'SYD']; I am working on Localhost: Windows, Apache 2.2.3, PHP 5.1.6 and MySQL 5.0.24 here's the original code: http://www.php.net/manual/en/function.curl-multi-exec.php Regards! hugo Hiram. ---