The new feeder design has a slide plate that the end turns up on a slight angle to help push fine into feeder in theory. The old style slide plate was just a straight flat edge. What we found was the slight angle up on the end of the slide plate actually lets fine slip under the slide plate. They build up under the plate and the beveled edge comes up and contacts the top of the feeder and does the "nails on the chalk board" effect. We flattened the end of the slide plate so it was like the old one and it has not squeaked once. Harman knows what our solution was, I dont know if they have done anything about it yet. Hope this helps someone, Or give the you fellow service techs some info to go to Harman with. Most of the time you get "You are the first One to call about that" ????