I'm sorry, but I only see a single cart button on the page you included. The button on your page currently does not work, because the item ID of the code no loner attaches to a product in your account. You will want to re-copy and paste the button code form E-junkie to your site.
I did checked your E-junkie account and you do have only one product listed currently.
If your cart is opening with multiple products in it, start by opening the cart and then removing all the products. After that try adding the one product in to the cart to see if that works.