I'm having some problems getting payments to process via Authorize.net. I am a bit stumped because I have other Joomla components functioning properly through Authorize.net

When attempting to pay for a membership, users see the following message:

HTTPS POST Connection to payment gateway server failed (check system information in CBSubs Settings): ERROR: Error: cURL could not retrieve the document, error 60. (0)
HTTPS POST Connection to payment gateway server failed (check system information in CBSubs Settings): ERROR: Error: cURL could not retrieve the document, error 60. (0)

CBSub logs show additional info:

authorizenet Single payment error returned 8888

I have verified my Authorize.net API login information and have re-created the payment gateway in CBSubs with no luck.

Any ideas?

This error is also occurring with PayPal as well, after payments are made. So obviously there's something wrong with Curl but I don't really know where to start...