When I click the 'Proceed to Checkout' button ...

it just loops back to the same page; however, clicking the 'Next' button shows the checkout procedure and appears to work fine. The 'Proceed to Checkout' button is in the cart module in sidebar-a, while the 'next' button is in the main module that comes up for the listings.

I'm not sure, but I must have done something wrong? I am new at getting things like this set up. I have the starter program.

I do appreciate your help! Thanks for this great program!