How often are you connecting to it and how many times are you connecting each time? They may have some custom code to forward IPs that connect to often to older RSS feeds. You can also try setting:
PHP Code:
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
to
PHP Code:
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0);
and see what happens.