Checkout page will only refresh

When adding an item to my cart and trying to checkout, the only action that happens when pressing the "checkout" button is a refreshing of the screen. No error messages when I use the Pavilion theme but when I change back to the Defualt theme I get "error" and that is it.

Using version 1.5.6.4
Pavilion Theme
www.shamrockholsters.com

I see on another earlier post that Daniel may have posted a fix for this, but I can't seem to find it.