I fixed it!
You were half right Jordan. They were blocking me, but not because I was connecting too often. It was because I had a blank user agent header. Apparently, some servers don't like that. When I spoofed my user agent as Firefox, it worked perfectly.
Thanks for the help.
Here is the additional code for anyone else with a similar problem:
PHP Code:
$useragent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1';
curl_setopt($ch, CURLOPT_USERAGENT, $useragent);