This is related to the "hard disk not found" error that you reported in another thread recently.

A long pause on "building music databases" means that it's having trouble reading the database files, or they have become corrupted. After you correct the hard disk trouble you're having, then you must repair the music database by hand.

The freeze while it's trying to play a track is most likely just because it's having trouble reading that track from the hard disk. If, after you've solved your hardware problems and rebuilt the database, it still freezes on that particular track, then make it skip that track to get the player working again.