I'll go with shaneystar on this one. Put some vinegar in the dispenser where you normally put your dishwasher tablet & then run a normal wash, with the dishwasher empty. That should cure it. Also, have a look where the door meets the body of the dishwasher - sometimes you'll get a load of slime & gunk there (just wipe it off). If you do the vinegar thing regularly, as shaneystar says, it keeps the dishwasher fresh & clean & is a lot cheaper than the cleaner you buy specially for them.