My GE microwave was acting up tonight. I was heating something for 10 seconds; I stopped halfway and opened the door. When I shut it, it automatically started back without me pressing start. I also noticed it read "6:50," which was the time - not the countdown timer like normal. It's done this a few times since tonight.

Basically, is anything wrong with it? What's to keep it from spontaneously heating and perhaps catching fire? Should I be concerned at all?