Do you have your Contacts linked to iCloud?
Sidebar: I had address details in iCloud and also in Google. When I noticed duplicates in Contacts, I started deleting them. Then, I noticed that addresses were deleted from my Android cell phone. I have to have a copy in each source: iCloud and Google, and they show up as duplicates in Contacts. A change in one has to be changed manually or copied across to the other.
I suppose if I had a $1,000 iPhone, the problem would be solved.
Edit: BTW, I've never used Address Book, yet I have a folder in Application Support named Address Book that has a configuration plist with yesterday's date. Maybe Apple changed the name of the application, but not the support files?
