Okay -- it appears that CURL works fine for HTTP and HTTPS/SSL, but does not work fine on port 1129 which is required for linkpoint. See the timeout here:
http://www.fastceus.org/products/cur...t:1129/LSGSXML
You'll need to get your hosting company to open port 1129 on their firewall.
FAQ: https://www.zen-cart.com/tutorials/i...hp?article=298



