The situation appears to be improving. Consumer Reports tested more than a dozen dishwasher detergents and did not detect the problem.
Another test checks to see how well the detergents clean away food. A messy mix of 17 ingredients, including peanut butter and eggs, is applied to plates, then baked on. Testers also coat pots with macaroni and cheese and bake it on.
Some of the worst performing detergents left food on the plates. The lowest-rated detergent: Green Mission Organic Dishwasher Gel from Whole Foods.
But Cascade Complete with Dawn ActionPacs was a clear standout. And Great Value Powder Pacs from Walmart was close behind and costs far less. Both do a very good job cleaning dishes, and they don't leave a filmy buildup.
In addition to choosing a good detergent, Consumer Reports says there are a number of things you can do to get your dishes cleaner, including using a rinse agent, facing the dirty side of the dishes toward the water jets, and separating your flatware.
Complete Ratings and recommendations on all kinds of products, including appliances, cars & trucks, and electronic gear, are available on Consumer Reports' website.