Getting Project Diva 2nd/Extend to recognize music?

[damdaladancin]

There's a feature in the Project Diva games (which work wonderfully, by the way) where you can import a song into the game and make custom edit data with it. I'm not entirely sure how, though. Whatever I do, wherever I put the mp3s, the game doesn't recognize that they're there.

Any ideas? I figured this was as good a place as any to ask.