everyone else has given you good info. but something esle for you to consider is, there is always water between the dishwasher and the disposal even if you run the line up high or if you are using an airgap. what keeps that little bit of water in the hose (and any water that goes into the sink) out of the dishwasher is a valve that only opens when the dishwasher is draing. i think that the valve is slowly leaking and that is why you are getting the water in the dishwasher. i think you should call a repair person.