iTunes can't sync contacts as contacts has been disabled on iPhone I am getting this error message. 

itunes can't sync contacts as contacts has been disabled on iphone


Configuration: iOS 6.1, iphone 4
back up address book  [File>Export]
delete all contacts in address book
delete all files within: library>user>application support>address book
untick "sync contacts" in iTunes - click on "Sync" button
open address book: import file (the backup file)
open iTunes: tick "sync contacts" - click on "Sync" button