Hello, I thought I'd add a post in MacRumors as well, since I didn't find any help on the same thread over at Apple's discussions... Well, here it goes. Let me know if you have any ideas on the matter! Since I got my iPhone 3G, and paired it with my bluetooth headsets, people have been complaining that they couldn't hear me well. My voice would crack up, or even not make it at all to the other side. I got a couple of new bluetooth headsets, only to find out that it wasn't the headsets' fault. That said, I would like to add that all the headsets that seem to misbehave when paired to the iPhone, work great when in use with my older SE mobile phone. I did some testing and found out that, the issue of my side cracking up or not sounding at all would only arise when the OTHER party was in a noisy environment (usually trying to talk to somebody in a Mall would do the trick). I would also like to add that when talking through the iPhone itself (even on speakerphone), would work fine! I am suspecting that there is an echo cancelation feature build-into the iPhone that revs up when talking through a bluetooth headset and seems to cut-off my headset's input level when strong noise it detected from the other side, presumably to avoid echo. Seems like this feature is badly tuned, in a way that communication can no longer work in an syncronous way. What seems strange to me is that, after updating to v2.2 of iPhone software, the issue seemed to have gone away; however, it looks like it's back! This whole situation could also be connected to various bluetooth quality issues many people are facing when using bluetooth car kits. I would suggest you try and connect such issues with the NOISE on the OTHER END. I managed to put together an audio file of what's happening here... I used Audio Hijack Pro to record a Skype call. The noise you can hear playing through the MacBook's speaker is the file "Lobby Conversation.caf" found inside Apple's iLife audio loops. The mac is sitting on the desk, playing the ambience sound, while I have moved to another -quiet- room answering the call. I later tried un-pairing and then re-pairing the bluetooth headset and this has cleared the sound a bit, I now actually have input from the headset, still cracking-up, however. Anyone facing similar problems could try it out and let me know. P.S. My brother as well as a friend of mine are facing the exact same problem. Since I haven't found many forum threads regarding the issue, I am starting to think that a) either people aren't using bluetooth headsets with their iPhones or b) there are different bluetooth chipsets build into iPhones that behave differently (I would also like a comment on this). Thanx in advance for any input.