I just recently updated to iOS 6 (iOS 6.0.1) and did this Facebook-Address-Book sync thing. After that I manually went through all my contacts, combined the duplicates and chose the Address Book / iCloud names as the defaults. This is because a lot of my friends use weird names on Facebook. Everything seemed to work. Now, all the names in my Address Book reverted to the Facebook names, for no apparent reason. Is that a bug? Did I do something wrong?