take the detergent back Costco takes even the empty container! we use cascade too.

The eggshell thing is completely true. Also, the first time I removed those spinning arms to clean them I was appalled. I actually had to go at the little holes with tweezers because egg from the bowls I used to make omelettes had dripped into them and cooked during the cycle, blocking them completely!

I have a kenmore dishwasher made by bosch. When phosphates were removed from the detergents it stopped cleaning dishes well. I ended up switching to the finish powertabs, too. Costco has a coupon on them till the 8th, IIRC, and will take your old detergent back if you return it.

I've got a Kenmore dishwasher, too, it's 6 years old. Hate it with a passion, we have the exact problem you do. Will never buy a Kenmore again....

Finish Powertabs, OP. They're the only thing that works.

Although I pretty much wash my dishes before I put them in the dishwasher, anyway. I'm a complete freak about clean dishes.

OP here. Thanks for the input.

Just did a little bit of internet research to try to date the dishwasher (it was here when my husband bought the house). It appears to have been manufactured in 1995. So... we might be due for a new one.

But, I'll take a look at the spinning arms just in case that's part of the issue too.

You might not be crazy and your dishwasher may be fine. A lot of people have developed "problems" with their dishwashers with the phase out of phosphates in dishwasher detergents.
http://www.npr.org/2010/12/15/132072122/it-s-not-your-fault-your-dishes-are-still-dirty

Phosphates are great stuff - they help chew through sticky, dried and greasy food across a wide range of water temperatures no matter how hard/soft your water is. Unfortunately, it is also bad for the environment which for us means the Potomac River and Chesapeake Bay.

The reformulated detergents seem to be more picky about the hardness of your water and the water temperature. Before you could easily recommend a particular brand (Cascade Complete) and know that it would work for almost everyone.

After checking to be sure your dishwasher filter and spray arms are in good shape, start experimenting with different brands. We switched from Cascade powder to Finish Powder after enduring months of white film on our plastic, blackened pots and generally lousy performance.

We have lived in our house for 15 years and the dishwasher wasn't new. It still works fine. I generally use Cascade but my mom just told me Target brand is rated very well.

Check the spinning arms (don't know the name) that fling the water around as they rotate. If the water holes are plugged, then the water isn't getting around well and the machine can't clean. All kinds of food, eggshells and general grossness get trapped in these over the years, and things like eggshells never dissolve on their own. You can take the spinning arms off on our model (Bosch), clean them out, and put them back fairly easily.

We had some smell issues with our new dishwasher, and the GE guy who came to take a look said it really pays to use name-brand detergent.

Especially as dishwashers become more energy-efficient, they use less water in each cycle, and often things don't clean fully. He also said the cheap stuff contains different ingredients and performs far worse than no-name brands in all the Consumer Reports tests.

So he recommended liquid/gel Cascade, but just the regular kind -- not the kind with "the power of Dawn." Not kidding. He was that precise. He also recommended using a rinse agent in the other compartment. He said it helps get that last film off the glasses.

Rinse your dishes better and start researching. You are about due for another dishwasher

Honestly your dishwasher is probably on the way out. applicances aren't made to last longer than 10 years anymore.

We do use the cheap, old-fashion, powder detergent and it works the best.

First world problem warning.

Seems like our dishwasher doesn't clean well. It's a Kenmore, about 10 years old. There's often residue on the dishes (I have noticed that oatmeal and hot chocolate are particularly bad). Does it sound like a dishwasher issue or a soap issue? I guess I could try a different soap but we have a ton of Costco/Kirkland dishwasher soap right now. I am wondering if I should be researching new dishwashers or just buying new soap. Thoughts?