Problems trying to order multiple items (specifically peaches) on the new site

When I attempted to add 2 peaches to my cart on the beta site this evening, it would only add one. When I tried updating the amount to two, the cart simply deleted the item (and yes, I hit the "update" button and not the "delete" one). I tried multiple times to get it to work, but finally had to give up and go back to the old-school site, which allowed me to add two peaches to my cart, no problem.