I have a 3GS upgraded with the new iOS4. Before the upgrade, I've used my Rocketfish RF-BTHP02 Stereo Bluetooth Headphones with no issue. After the upgrade, it shows 'connected', but I get no audio through the headset. I paired the headphones with my wife's 3G (still on 3.1.3) and it works perfectly. Is there a conflict with the new iOS4? I've read several threads discussing different bluetooth problems and wanted to track mine down to a hardware or software issue.