Contacts are not synced to Address Book on Mac running Snow Leopard

When syncing contacts to Address Book on Mac running Snow Leopard, contacts from the remote side may be invisible in Address Book if the latter does not contain any contacts yet (is empty).

To make the synced contacts visible, do the following: create a new contact (card) in Address Book on Mac. Do not forget to choose "Save" from the File menu when finished (or just click "Edit" button).

Read the instruction on how to create a new card in Address Book: http://support.apple.com/kb/HT2486