Cant use (no sound) when on Hands Free AND audio cable plugged in

[dtsig]

Things work great with Handsfree through my cars system. AND my S3 sounds great when the audio cable is plugged in and playing through cars system.

But when cable is plugged in and I get a call, the car tells me I have a call ... I accept it (press a button) and then ... nothing .. no sound through Handsfree or phone. If I unplug then try the call again Hands free again works well.

Anyone experience this? Is this a known problem?

Thanks