I read about the three day rule somewhere but I rang yesterday and booked two nights for December without any problem. I even asked the CM 'Do I not have to book three nights and a package to get the Disney Club discount' and she said no. I got about 20% off two nights at POR. The number I rang was 001 800 933 3975 (that was from UK so you will need to take off some numbers at the beginning)