windows live messenger problems

hi, ill try and evplain this.
when video calling i ysed to be able to hear my friends music altrhough he could bever hear mine. Now both volume controls next to wecams are disabled and neither of us can hear each others music but he can hear my voice. I cant hear his though. Neither of us think we have cganged anything. Does anybody have a clue what we can do, we want to be able to play music and chat again.
thanks

please can anyone help on this