I havew a frigidaire dishwasher that I bought about 2 yrs ago brand new. we had problems with the top rack not being clean and they replaced the main pump (under warranty). well, its doing it again. I decided to go at it myself and I noticed that the water supply for the top rack does not completely fill up - it has air in the top part of the tube. I also noticed that when it goes into top rack mode, it works for about 30 seconds then the water drain out and no more water goes to the top rack. Not sure why, but my guess is that the pump is not strong enough to supply the top rack with water - what does it sound like to you?