New kitchenaid combo oven and microwave kems378sss

I have just bought a brand new kitchenaid combo oven and microwave model # kems378sss . My problem is that when the microwave gets a the end of his cookingtime0:00, it make’s the 3 normal beep, the heating stop,** BUT the plate keeps on turning,the light stays open and the fan keeps on workind too. I bought thisoven/microwave in november 2 2011, they have come now 3 times to repair it and cannot find the problem.And now they sent me a new one,and still does the same thing. What can it be or what m i suppose to do? Do you think they have a problem with a part at the factory? Or did ever somebody saw that before?:confused:

If the second unit also does it maybe it’s operating as it should.

The first one was ok for 3 days, but the second one was like that at the first day.
But even that said, have you ever saw a microwave not stop after is cycle?

As i know, all the microwave stop after the time runs out, they didn’t change the way that it works!