My photos won’t synch in iTunes

When I connect my iPad to Itunes, the usual backup/synch process starts and goes through it’s steps, but when it somes to the part where it’s “reading photos” from my PC to synch to my iPad, it gets hung up, and stays in the “reading photos” mode all night without actually reading, synching, ot copying anything. I didn’t change any settings to make this happen. What’s the problem?