We had the same problem. I drained it completely by disconnecting the draining hose, dropping it to below the level of the water in the dishwasher then soaking up the rest with a dishcloth after removing the drain basket/filter at the bottom of the inside of the dishwasher, cleared out the remaining muck from the bottom and it worked again. See also answer to "My Indesit D4000 IN/DW9 isn't draining?"
David, May 2006