I have a stack of MD discs recorded as SP on the Sony MZ-N510 and the Sony MZ-RH1.These discs play on these two recorders. When I insert these discs in the Sony MDS-JE330,they are recognised by this recorder/Player but no sound comes out. An MD disc that was recorded and supplied with this Sony MDS-JE330 works 100% on this recorder/Player. Anybody has any answer ???.