I'm sure this is the height of stupid, but I'm at my wit's end. I have made a shopping cart located at the following website:
If you add any of those packages to the cart in Firefox, the customer can check out. If you try it in IE, you get an invalid value error, and nothing adds to the cart, but it does direct you to the empty cart. This is driving me insane, and so far I've failed in Googling the correct answer. Can anyone give me a hand with this? I'm on bended knee here.