I've downloaded two lectures from two different courses in my iPad. They are in my iPod/iTunes U app, but when I sync my iPad with the iTunes on my Mac, I can't see the files anywhere. It's as if the lectures weren't there. iTunes U shows no item at all in the iPad or in the Mac (I just have those 2 items in my iPad). I don't know what to do. How can I delete the items from my iPad, for example, if I can't access them on the iTunes on my Mac? That is bothering me a lot! Any help?