The 2Checkout purchase routine sets a cookie on the user’s computer when they begin a purchase. This cookie remembers what the customer had placed into their cart. This way, if the customer loses their Internet connection or is otherwise unable to complete their order, they are not forced the entire checkout process over when they [...]

The reason for the products to not be removed from the cart from previous purchase is because you have tested a demo sale more than once without actually completing the sale. This means the product was “cookied” into the cart. The cart will remember items you put in the cart, and will only clear out [...]