Missing photos when syncing from iTunes to iPhone
I have a rather random problem that appears to have only appeared since the release of the new Photos app. When I sync my iPhone with iTunes and select which photos I want to sync some are missing even though they are clearly sat in Photos. It is always the same pictures and doesn't matter if they are in folders, favourites or just collections.
Tera here appears to be no logic to this as they have all been taken in the past 3 months (the period synced on iTunes) and I've never had this problem in the past.
I can't seem to find anyone who has posted the same problem but please let me know if I've overlooked something.
Any advice gratefully received.
P.S. I do not use the cloud based services. This is a straight sync from the photos saved in the Photos app to my iPhone.
Thanks.
MacBook Pro, OS X Mavericks (10.9.5)