Snow Leopard 10.6. Address Book SELECTIVELY allows deletion of a multiple contact entry. The updating of the contact database, as as function of the installation of Snow Leopard, produces/creates/brings to your attention, multiples of some contacts that did not exist prior to the upgrade. Most duplicates or triplicates you cannot delete. Some will allow you to delete one but not the other. You can delete them using MobileMe or on the iPhone but not by using the Address Book.