I have restarted my browser and cleared my cache multiple times before I posted this thread, I was always getting the same error message. Since you added it to my cart, I can't try again without removing it from my cart. So I clicked on "Remove from Cart" and it gave me the same "undefined" error.

I'll try checking out. If I can checkout and the product shows up in my item history, then the error becomes irrelevant :)

I'll let you know how I get on.