I have a Kenmore Ultra Wash Dishwasher that is around 11 years old. It has started to leave bits of food stuck to the dishes on the top rack. It has a "food catcher" in the bottom of the unit that has worked great for years, but has obviously quit working in the last 6 months. I have used a dishwasher cleaner several times because we have moderately hard water and there is some calcium/lime build up inside the machine.

It sounds like you need to take it apart and clean it. Try running some scale remover through it first and see if that will remove the scale. DrTom4444