When syncing books on iPad, library shown in iBooks also contains books no longer in iBooks I add and remove books en PDFs to en from iBooks. When wanting to sync my books and PDFs on my iPad, through iTunes, the list of books and PDFs available for my iPad (from iBooks) shown under 'Books', gets larger and larger, as it does show the books and PDFs in and added to iBooks, but does not remove from that list the ones removed from iBooks. So, the list gets larger and larger. Very annoying... Does anyone know how to solve my problem?
Open iBooks, go to File and select 'Move Books from iTunes…'. This should fix the problem.