Unable to connect to checkout page

Alrighty, I am working the Instinct wordpress ecommerce plugin and cannot get my checkout page to appear. I keep getting the follow page when I click the link to my checkout page

Unable to connect
Firefox can’t establish a connection to the server at shopalloyjewelry.com.

The site could be temporarily unavailable or too busy. Try again in a few
moments.
If you are unable to load any pages, check your computer’s network
connection.
If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web.

All of the other pages on my site are working fine, all links connect and link back but for some reason the checkout page isn’t working.

Can someone shed some light on this problem?

I have tried changing the permalinks, deactivating and reactivating the plugin, still no luck.

Who’s go an idea?