They often (always I think) have two pumps - one to spray the warter around and one to drain it out. If your machine finishes with water still in it the drain pump is obviously not working as it should.
You can check the circulating pump by opening the door mid cycle - everything will stop immediately but if the circulating pump is working the spray arms will still be moving as they slow to a stop.
Inside the machine - right at the bottom under the filters at the lowest point - you may find a single screw. If you have a Torx driver you can take the cover off and see if any crud is trapped under the impeller of the drain pump. The impeller should rotate freely with a bit of magnetic resistance. I have found lemon pips trapped under mine - tweezers help.
Good luck...
Peccavi
June 2009