Tire cupping is not that "new" to Dunlop and there are plenty of threads on the subject. You can use the Search tab near the top and type in dunlop cupping for threads on the subject...
http://www.hdtimeline.com/brakes_tires_and_wheels/28334-09_touring_front_tire.html
http://www.hdtimeline.com/brakes_tires_and_wheels/28334-09_touring_front_tire.html