There are a number of threads on this (or very similar) problem. In another one it was suggested that the out of balance sensor switch had corroded and is the problem. This provided the clue I needed. The switch was OK but the connectors to the switch had the green gunk on it that you get from copper corroding. The moist area there causes grief. I just cleaned the connectors reassembled and it has been fine for a few months now. It is covered by the controller board but very easy to get at.
JayAre, October 2007