Yep - KitchenAid DW Food Chopper was clogged!
The configuration was not exactly the same as in the photo (different model), but I found the screw that, when removed, revealed the chopper screen and blade. It was full of pieces of plastic baggies, unpopped popcorn seeds, and other seeds. I removed it, cleaned out all of the seeds and plastic pieces, re-assembled it, and now the dishwasher runs like new! Top rack cleans everywhere. Question is: Why did Whirlpool keep this screen a secret? Cleaning this puppy will probably be an annual thing in my house! Thanks ApplianceJunk!!