Why is there white crust on my dishes after they are washed in the dish washer?
It sounds like the detergent not completely disolving.  Is your water hot enough (it is hooked to the hot water, right)? Does it take a long time for your hot water to reach it? Try running it in the sink before starting the washer and see if that helps. You could also turn up the water temp (be careful though if you have small kids). Switching to a detergent that disolves better might help, or use a little less. Try liquids vs solids. As a last ditch, it could be your water is hard and you need a softener installed.