it sounds like the Tama has something wrong with it- try a time out. if that don't work, well, it sounds like you need to reset it. wow, what stage is it??? I've never had this problem- except with my old Gen2 Tama, where sometimes it'd need food but it'd be stubborn and not eat. then I'd do dicipline and it'd eat... problem sounds almost the same.
-Shadowed Suit