Itunes (and my apple tv) says i have no purchased items, but I have.

I bought and downloaded to my hard disk 3 movies and several video clips from itunes store. Because a problem with my hard disk I moved all my library including the 3 movies to another hard disk. Movies are OK and I can see everything going directly to them in my itunes, but if I ask for purchased movies or video clips itunes says I have no purchased items, the same happens with my apple tv, so I can not see them in my apple tv. Any idea?

Thanks,