I'm wondering if my mic is knackered there is a constant background hissing noise whilst on the phone (the other person hears this). Also when you add someone to the phonebook and the HFT reads back your voice you can hear the hissing noise and its really quite loud. Next thing is half the time it can't understand my voice. Has anyone had these symptons and fixed it by replacing the mic? I know someone replaced there mic with a Nokia car kit one on another forum.