ok so i was having this same issue, im using ios 8 as well ...
go into your itunes and click on the little phone icon. Click on "photos", then make sure there is a little check mark in the "Sync Photos from" icon, choose the Desktop , and click apply in the bottom right of the screen . You should get a "remove ...message" and hit ok.
Then go back up and uncheck the "Sync photos from " icon.
Hopefully this will work for you!