ZenCart Credit Card module

Anyone use Zen Cart and the Authorize.net(AIM) credit card module on DreamHost?
I can’t get it to work for me; it doesn’t seem to send anything to my credit card processor’s site. The folks at ZenCart.com said I should check out the curl_setopt things that need to be set to work on DreamHost, but I’m not even sure what that means.

Here’s the part of the module that mentions curl_setopt ($url is an actual URL):
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_VERBOSE, 0);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
$authorize = curl_exec($ch);
curl_close ($ch);

I read the DreamHost Wiki on cURL, but I don’t understand what needs to be done to actually make this work.
Any help is really appreicated!