Kitchenaid dishwasher has white scum

Our dishwasher is leaving a white scum on the dishes. I have tried different soaps, jetdry, vinegar etc and it seems to be getting worse. Could something is plugged? Help please.

Here is a good link
http://www.applianceaid.com/dish.html

Check out #28

Check your water temperature, it should be a minimum of 120 degrees F when filling the unit.

Check that the heating element is working.