I'm having issues with my Plantronics Voyager Pro (headset) and my iPhone 4. Bottom line is people can not stand to talk to me on the headset. It sounds so muffled, and crappy they can't deal. With my 3GS it worked perfectly, and we tested it again with my wifes 3GS. Can Apple do anything right on this phone other then get us in a frenzy to buy one! I called Plantronics, and basically they confirm it's an issue WITH THE IPHONE BLUE TOOTH ANTENNA! I'm so frustrated with this wonderful antenna system, and Apples lately near lies about what the problems are! I'm a loyal Apply user and I'm getting pissed.