Sony Radio drives me crazy

Hi, I posted here some time ago that my Sony Radio L350 always beeps three times when I turn off the ignition of my Golf 4. I have managed by now that the radio does not always give a beep tone when I turn up or down the volume, resp. choose another transmitter. Only I can not get the beep away when I turn off the ignition. Does anyone know if you get the overhaput away? MfG…