A friend has a PB G4 and when I speak to him via Skype and my G5 and my headset and his internal mike, I get a lot of echo. He doesn't hear any echo. I'm the only one. What do we (or he in fact) to make the echo disappear? He's the only one with this problem. I don't have it with others who also have a headset. Is it necessary to have a headset? Paul Moortgat