I'm running iOS 9.3.1 on my iPhone 6S and the latest iTunes and I've discovered that every time I do a phone sync to my pc, iTunes is recopying my entire iBooks library to my phone which is a pain. This happens even if no changes to my iBooks on my iPhone. Seems it has only been happening since ios9 I think. Any suggestions on how I can get it to stop? I've tried flipping on and off 'Sync Books' in iTunes, logging in and out of iBooks, but nothing seems to help. If I flip off 'Sync Books' it erases all iBooks from my phone. Any help would be most appreciated.