I have a 6 year old Ultra Wash dishwasher. When I push the buttons to start it, none light up. Then, it mysteriously starts up on its own a few minutes later-only to stop again after running some part of a cycle before the buttons go dark and it stops. I checked the Trouble Shooting section in the manual and this sort of behavior was not listed... oh, oh... Any thought as to what might be going on? Thanks