Can't Add Another Item

Team WPMU,

I had a complaint from a customer that they couldn't add a second item from a store. They could select to buy the first one, and then would be taken to the shopping cart (per design). But, if they clicked "continue shopping" and added a second item, they would again be taken to the shopping cart, but the item wouldn't be there.

I did the same thing, and got the same result - no second item.

After fiddling with it a while, I refreshed my browser while on the cart page and saw my missing items.

But, obviously, the shopper didn't do this - and why should they? It should just work and their new item should be showing when they click to buy it.

What can be done to force the shopping cart to refresh when a new item is added so that the buyer isn't confused?

Thanks,
Rob

P.S. Store in question is http://www.nickcolebooks.com/my-books/store/