Well, it wasn't necessarily bad...it was more of a regular thing that the boom box might do...other times your tama might start dancing, and then the boom box won't blow up...
Oh, and polar12: you have to go to your item screen, and then use the boom box, and then the CD will automatically go into it.
i just selected the music cd in items menu and then it magically floated into the boom box and then there was a cloud of smoke and the boom box was gone and my tamagotchi was sad