there really should only be 1 reason for water dripping when the machine is not switched on, and it is an easy fix. the fill solenoid that the water supply hoses attach to is passing water. this is usually due to a small piece of debris in the diaphram, or the diaphram itself is perished. easy way to find this out is as follows...
turn the power off to the machine at supply (unplug from wall), if you still hear the dripping its simply a matter of replacing the solenoid. if you no longer hear the dripping sound there is a small chance there may be a fault with the PCB board of the madhine allowing a small current to the fill solenoid. to find this out you can disconnect the wires from the solenoid (again with the machine unplugged). power the machine back up and listen. if no water then its the board.
id place my money on it being the solenoid though, its not uncommon to have this happen
tony, February 2009