I got a Jabra BT2020 bluetooth headset. It works perfectly with my iPhone, PS3 and some other cell phones. But when I use it on my Mac Pro (OS X 10.5.4), I can hear everything but when I speak through it, I only hear static (like if there's a wasp in the line). I even tried to lower the input volume in the audio control panel, without result. The graph that displays the current input level, is always completely filled. I also tried to remove the headset from the bluetooth list, and then adding it again. But that's not solving it. When I try it with Vista (using Bootcamp), then the headset isn't even recognised (so there I don't even have output through the headset). This problem is happening with both of my headsets (Acer VoIP phone is the 2nd one), and also on my Mac Mini. So it might be an issue with the OS.