Product review (5 stars): Dexter's review was gold!
I sure appreciated Dexter's review.  Saved me $50 at the local appliance parts store!  Turned out that a 30 year old manual shut-off valve just upstream of the dishwasher fill valve has a rubber seat that was breaking apart.  The fill valve worked great after a careful cleaning, but immediately plugged with more gasket pieces and underfilled the dishwasher the second time.  I am off now to get a new manual shutoff valve since I couldn't get the old one apart to change the seat.  Note that I also did a flush of the piping to the dishwasher and was able to obtain about a third of the gasket in the flush, plus a visual looking up the upstream side of the valve verified that only a small part of the rubber seat was still there.

I discovered that there are actually two devices upstream of the valve that can plug, and both are removable.  The first is the inlet screen, the second something that has a black rubber gasket associated with it that I think limits flow so you don't overfill the dishwasher.  I found that was removable when I blew threw the outlet of the valve and blew the assembly across the room.  I think it could be better removed with a needle nose pliers.  Thoroughly clean each piece with a combination of water and compressed air. and reassemble.

I actually think the upstream screen is protecting the flow limiter from plugging as opposed to being there to protect the actual valve.