[SOLVED] Why does PHP's cURL appear to 'timeout' on certain URLs?

Why does PHP's cURL appear to 'timeout' on certain URLs?

I'm using PHP's cURL to get some tag information from various URLs. My requests work some of the time, but other times they don't work at all. Is there some reason why my code doesn't work? (Note that I'm also using simple_html_dom):

$webpage = 'http://www.some_url.com';

$curl = curl_init(); 
curl_setopt($curl, CURLOPT_URL, $webpage);  
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);  
curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($curl, CURLOPT_FAILONERROR, true);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($curl, CURLOPT_AUTOREFERER, true);
curl_setopt($curl, CURLOPT_FRESH_CONNECT, true);

$str = curl_exec($curl);  
curl_close($curl);  

$html = '';

if( !empty($str) )
{
    require_once( 'simple_html_dom.php');

    $html= str_get_html($str);
    $element = $html->find('h1', 0);
    $webpage_name = strip_tags($element);

    $item = $html->find('meta[name=description]', 0);
    $description =  $item->content;
}

// save $description to database
// save $webpage_name to database

For about half the URLs I try, the description and webpage_name are stored in my database, but for the other half, they are not stored, and the script just stalls. That is, when the user submits a URL to my website a progress bar is presented while the URL is uploading to my site. Then, the progress bar disappears and the URL is displayed on my webpage for the user to see once the URL submission is complete. For troublesome URLs, the progress bar goes away, but the link doesn't appear on the page and nothing is stored to my database. What am I missing?

Solution

My error log is saying "Call to undefined function mb_detect_encoding()". This function requires that the mbstring extension is enabled (it is needed by simple_html_dom.php). MAMP does have this installed by default, and that is why it works on my development server, but not on my production server. I have put in a request to have mbstring enabled on my Linux production server, so I'll let everyone know if this is in fact what the problem was. I have seen several posts online with people having the same problem, so I hope this will help a lot of people.