Boy I wish I knew the answer to your query and then I'd be able to sync my ITouch to ITunes on my MAC.
I love the Mac and its performance in so many ways but some of its software is either so out of touch with reality or I'm not in touch with the 20 year old techies that design and find its software very simple.
Now and then I find success in my sync and have no idea of how or what I did so I could duplicate it.
OK, I know I'm blaming the world for my shortcomings but in BM (before Mac) I was the go to guy to help people with their PC problems.