Model DU920PFGB1 Whirlpool Cycle Wash Plus: The machine does not drain out completely after it finishes washing. We scoop out a bit over a gallon's worth of water. We can still run subsequent loads but still have to scoop out water afterwards. In fact we're running a load now. The first time we noticed it we did find some paper at the bottom of the machine. As best we can tell there's no other debris. Any suggestions?