I hope this isn't a silly question:
but..
Have you accidentally renamed a folder so that the link to these songs are incorrect therefore obviously your media player can't find them?
I really doubt it will be anything to with downloading them of bittorrent (which you shouldn't its illegal) unless they have some seriously clever DRM in them.. but don't worry about that.
Try cutting them from their current place on your pc and putting them somewhere else. Then uninstall Itunes and download it and install it again, then sync all you music into it again.
I can't see a reason why this wouldn't work.
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Nearly a Posting Virtuoso
Offline 1,282 posts
since Oct 2005