XPS 17 won't shut down???

I'm baffled - my brand new laptop restarts every time I tell it to shut down. I tell it to shut off, it powers down then immediately starts back up. If I hit the power button as soon as it lights back up after power-off, it'll shut down but I shouldn't have to do this. Has anyone else seen this behavior? Does anyone know how to stop it? The laptop itself is fantastic and gives me all the horsepower I need, but this bug is really bothering me.