It sounds like there is a wrong connection on the rear of the unit. On some audio systems there is a connection that links a hands-free phone kit or car-kit to the cd player/radio etc to mute the audio when a call comes in, or in some systems it wll route the entire phone call through the car's audio system depending on the hands-free kit. It sounds like this connection has been used by mistake.
If you installed the unit yourself then get the instructions and look for the appropriate wire. It should be taped up to stop it earthing accidentally (as should any unused connections). If it's a factory fit then it's got to go back as unless the back of the player has the wiring diagram on it, it's difficult to know which wire is which.
Karl, August 2007
