hi
i have smilar prob with mine. i took out the spray head at the top inside the dishwasher (comes out easily -half a turn) and cleaned it by blowing through all debris. then i took out each of the rotor arms and did the same. cleaning them was a bit harder and sucked out some of the grains of food (yuk), and thoroughly cleaned the filters etc.
After that I poured in a whole 500ml bottle of cheap malt vinegar (15p from ASDA) into the machine and ran it empty for a full hot cycle (for pans).
That seemed to do the trick. I suppose I could have used the diswasher cleaner from finish, but its nearly £3, ans vinegar seems to do the job.
don't know if that will fix your problem but good luck.
LR
November 2007