It looks like Rarewaves ships out of the U.K., just like Chalky's. I've ordered from both with no problem before. This time, Chalky's sent me a message:
"Hi there - we noticed you have purchased a DVD or Blu-Ray which is region encoded. Region 2 DVDs and Region B Blu-rays are designated for the European market and you will need to make sure your disc player is multi-region capable. If it is not you may need to cancel the order."
I don't have a multi-region player, so had to request a cancellation. It seems I am destined not to get a physical copy of this release. Good thing SW is so successful, as he's not making it easy for me to give him my money.