iTunes sync will not remove audiobooks
When I sync my iOS 7.1 iPhone 5S with iTunes 11.1.5 with my iMac running OSX 10.9.2 suddenly previously loaded audiobooks which I have now unchecked are not removed from my phone.
This just started happening yesterday after working properly for over a year. I have reset my phone and quit and restarted iTunes but it is still happening.
Any ideas?
iPhone 5s, iOS 7.1