same thing happened 2 hours ago to me.
I had to tilt it backwards, a lot of water came out despite looking empty. I pushed the buttons till it was steady on rinse closed the door and after 2 or 3 minutes of the pump going it started again,
I had first to unplug it. Turn off the water. take of the water feed( it was easier to do this at the sink end) and the drainage into the sink as these were to short to allow me to pull it out of the hole to allow the tilt, there were a couple of screws going into the work surface just in front and above the dishwasher door which i undid first.
Paul, May 2009