The full answer is in the Mac support forum. Should still be right near the top, and easy to find by subject.

Short version: get yourself a copy of MP3 Rage, drop the file on it, and change the type tag to
SITD
and the creator tag to
SIT!
All caps, and you do need the exclamation point.

YOu can use any Mac type/creator changing tool you want, but MP3Rage kicks ***, because it's designed to make it really easy to fix the tags on your MP3's, and the more people who fix their tags, the better it will be for all of us.