Anyone else had this happen? I bought this soundbar less than a week ago, and it's two optical inputs are hooked up to a Humax PVR and Panasonic BluRay. I think this model powers itself down automatically when you switch off the attached devices, but I don't think it should be happening while you're watching a bluray! It's not happening constantly, about once or twice during an evening, but that's enough to make me think about taking it back. Have I bought a dud, or is this a common thing with LG soundbars?