6/5, always wanted to ask, is that your height?
This problem could be a number of things, or it might not be a problem at all. Some/most dishwashers allow a small amount of rinse water to remain in the bottom after the full cycle. Although it sounds like you are noticing this problem as being unusual. Scott has alot of good ideas, some I've never heard of(thanks Scotty) but a quick check and frequent problem that has not been mentioned is a clogged or semi-clogged "return valve"(called many different things) which is generally located on top of your sink. Pull the decorative cover off, unscrew the unit (generally plastic) and pull the cover off(this may take some doing as they are meant to be a compression fit so the water pressure doesn't blow them off). Many times you will find, toothpicks, pieces of plastic, labels from food containers, etc. stuck in there and this will prohibt all the water from running out.
If you are experiencing leaking out the front or suds coming out from below, you are probably using to much soap, which will cause a PH imbalance and thus create this problem. I myself succumb to this annoyance on occasion, "thinking more soap, cleaner dishes"

One cup of acid (real Lemon juice) run thru a cycle will take care of that. Feel free to ask of me any building/property/maintenance questions, happy to help my fellow MJ' ers
Hope that works 6/5