Hi, we had (and still have) exactly the same problem. It's an electronic protective arrangement that stops the machine should water get into the electronics. Turn the machine off at the power supply and remove the power plug. The bottom draw can be removed by pushing in the two clips found at the front/sides/bottom of the draw.
Now, being careful of the under draw hose/wires etc, pull the draw towards you slightly and then lift the empty draw up and over (say) the left hand support runner and rest the draw on that and the floor. You then have access to the inside base. (push the other runner in, out of your way)
Mop up the surplus water with a towel and leave to dry completely for a few days. The 1st time I did this it worked for about a month or so until the problem reappeared. I eventually found the problem to be a pin hole leak in the bottom draw hose. (which I've repaired)
Since then I have not been entirely successful in repeating the repair. (fails after and hour or so) I think I'm still getting some moisture occasionally.
You may have a leaking draw seal causing the same problem.
Anyway, good luck with it. (and don't buy another!)
Mechman
August 2008