Sounds to me like your original issue was caused by a short circuit in the power button causing the button to act as though it was pressed and held causing the question box to keep coming up. Probably, the switch un-stuck or stopped short circuiting and that's why it's acting normally now. I hope it stays that way! Unfortunately, I wouldn't count on it. I would take it to a repair center and have it checked. Or, if it is really new take it back for an exchange. That's my (long drawn out) two cents.
