Dishwasher Leaving Dishes Dirty and Cloudy Looking?

I have a nice dishwashing machine, but some of the dishes don't come clean after 2 or 3 times in the cycle. I don't understand why. It is especially in the glasses that seem to have some kind of "sandy" material on the sides and in the creases near to the bottom on the inside. The silverware is coming through looking cloudy and with bits of food still clinging to them.

This is "not" stuff going in on the items, as I rinse and sometimes wash the stuff before putting into the dishwasher. Any ideas on what could be causing this or how to fix the machine to stop this? Thank you!

By Deborah from Lebanon, ME