itunes is not syncing photos to iphone

Hello,

I am syncing 2 specific smart albums from photos app on my Mac to iphone using itunes. However, not all photos are synced.

The photos in the albums are 10K images, but only 7-8K were synced.

I tried removing the ipod photo cache and itunes pref. files with no luck. The synced pictures vary every time i try to fix this. sometimes 7.8K are synced, other times 8K, etc.

PS:

- I still have 6GB left in the iPhone, so it's not a capacity issue.

- all pictures used to sync previously. I noticed now it only syncs up to a certain picture every time. As if it does not sync after this picture (or this point in time).

- the largest smart album is 8.9K. Some pictures are overlapping between the 2 smart albums but I should get at least 8.9K synced

help?

Thanks