We have had this issue with Colorsync for quite sometime. After reading the Tech Notes and the posted link by Mark Dubovoy…presto clean printing. I changed the color settings to match Photoshop. I always suspected there was a setting under-the-hood.
But it was time to revisit it again because we kept hearing from more people who were experiencing this problem. I think especially with the addition of CS 4 and Snow Leopard, this problem was more common than ever!