I don't know what's going on, but I simply added some "view cart"/"proceed to checkout" buttons to some of the pages on my site (http://welding-tv.com/the-store
). It was working just fine up till now... When I add one item to the cart, it pops up this window, with a correct cart on top; but the bottom cart shows two of the item. If i try to checkout using the bottom cart, it says my cart is empty. But if i use the top form, it actually shows two items on the checkout page, though i only pressed "add to cart" once, and only one was displayed in the cart.
Help! About to run into some major problems due to this. It's probably user error... but i have no idea what caused it.