I removed the button by customising the template files...
also, i still believe this is a caching issue -
you changed the theme..
i visited your site again, which did indeed change to the 2012 theme... i pressed the add to cart button and when it did the redirect (NON AJAX due to 20120) for the success messaged your site re-appeared in the superstore theme again on the cart page...
it would only do this if it there was caching enabled... as this is nothing to do with the woocommerce side of things...