Hmmmm, I was surprised to be able to use my PIN online but it worked just fine. I had to type in last name and address to match to the PIN -- maybe your info doesn't match up to the PIN? In any event, I'd call and try to book that way. I did end up calling in the end to make my reservation, but I gathered all my info beforehand by using my PIN to check a bunch of resorts and rates at the 40% discount.