无法使用Curl下载URL

我正在尝试使用以下代码下载URL: http://es.extpdf.com/nagore-pdf.html。但是我得到的状态码是0。但是当从http://web-sniffer.net/访问它时，它显示301重定向。我的代码似乎工作良好的301重定向url也是。

有什么问题吗?

<?php

print disavow_download_url("http://es.extpdf.com/nagore-pdf.html");
function disavow_download_url($url) {
    $custom_headers = array();
    $custom_headers[] = "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
    $custom_headers[] = "Pragma: no-cache";
    $custom_headers[] = "Cache-Control: no-cache";
    $custom_headers[] = "Accept-Language: en-us;q=0.7,en;q=0.3";
    $custom_headers[] = "Accept-Charset: utf-8,windows-1251;q=0.7,*;q=0.7";
    $ch = curl_init();
    $useragent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0.1) Gecko/20100101 Firefox/9.0.1";
    curl_setopt($ch, CURLOPT_USERAGENT, $useragent); // set user agent
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    //curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $custom_headers);
    //these two from https
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 15);
    curl_setopt($ch, CURLOPT_TIMEOUT, 10); //timeout in seconds
    $txResult = curl_exec($ch);
    $statuscode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    print "statuscode=$statuscode'n";
    print "result=$txResult'n";

}