Had to call in an engineer. The solution:-
The machine was not level, tilting forward and water pressure was too high.
Bob McNally, April 2005
Turn the cold water pressure down on the supply pipe. the mains pressure is too high.
Charlo, April 2005
I assume that the machine is over filling!!
In which case I suspect that you either have a faulty pressure switch or the bottle chamber of the drum is blocked, thus not enabling the pressure switch to operate as it was intended.