As of today, both seasons 4 and 5, both released as Amazon Exclusives, have the following on their product pages...

"Notice: This title cannot be shipped internationally."

My order has not yet shipped, and I'm not going to be a happy person if the order is cancelled. I will definitely not be ordering from Amazon again.

Note, the product does not have the usual shipping restriction notice, meaning international customers can go through the checkout with this item and select an international address, even though they claim the item cannot be shipped internationally.

I changed to a US shipping address, and almost immediately my order status changed to indicate the item was being prepared for shipping. I wonder how long Amazon would have taken to tell me they weren't going to ship the items to me.