I have a maytag dw mdb9100aww and the adjustable upper rack (right side) keeps coming out of the wheels. The metal bar always pops out of the wheels. I am wondering if it has to do with the adjustable part that we never used nor was there. Is it supposed yo lock in up or down position? There is a handle that is mounted around the top of rack that does not do anything. I look in the manual and it refers to a handle that is used to adjust the height but my handle as I said is mounted around the wire rack itself. Any ideas what is wrong as the dishwasher runs great but this has been a problem for a while. Thank you for your time