I am having the same problem synching pictures only (not music, video or podcasts) located on a Buffalo Linkstation Pro, and the problem is with my iPhone and Apple TV. I recently moved my files to the Linkstation L drive from a smaller Western Digital D drive (Library still on C drive). Synch worked fine for severl days on both the iPhone and Apple TV, but then it started to hang synching pictures. When I move the pictures back to the WD D drive or to the C drive, the synch works perfectly. However, iTunes will not synch pictures located on the Buffalo Linkstation L drive (which does show up as a shared drive, too).
Appreciate any advice on this as I have very large files and need he storage capacity of the Buffalo Linkstation.