What's causing this?

try some salt and wash it empty

colcox
September 2010

Wikipedia has a good article on Dishwashers.

Salt, Rinse Aid & Detergent all play their part in efficient washing.

The detergent and the heat sometimes cause cloudy hazing on glassware - permanent & impossible to remove.

Debris stuck to the dishes is just broken down food particles (sometimes small pieces of lime-scale too) baked on during the drying process because of lack of rinse aid.

Peccavi
September 2010