Cannot Sync Contacts

I am encountering the same problem. I cannot sync my Address Book contacts to the iPhone. Changes in contacts on the iPhone, do not show up in my Adress Book either. Interestingly, iTunes does not show any of my contact groups either. I would really like to know how to fix this.

Mac OS X (10.4.10)

I am using a macbook pro and it took me 15 tries divding the address book into two parts to get it to sync. I still can not get it to sync with my bookmarks, music and photos. I have given up, tried 25 to 30 times, no luck, I own 50+ mac's in my business and I have never bought and apple product that gave me this kind of trouble, very upset, no help from apple, any idea's?????

I tried resetting the iPhone, rebooting the macbook, reinstalling iTurnes, resetting sync history, removing the plist files for Address Book, removing the Address Book cache, telling iTunes to replace the contacts.

Everything was to no avail. I still cannot sync my contacts on the iPhone. One interesting aspect seems to be that iTunes does not see any of the groups I configured in the Address Book.

Finally, figured it out. Renaming:

~/Library/Application Support/SyncServices/

to something else and then resetting the sync history with iSync solved the problem. The iPhone is finally syncing contacts correctly.