After I've been on the phone for about a minute, the earpiece starts making this loud whistling noise, and usually the person on the other end can hear it too. Is this a known issue right now or is it defective? It hasn't been 30 days since I bought it yet, and it's insured, so I should be able to do a free swap. Also sometimes the GPS won't work, it'll just sit there on a searching for GPS screen. First time it happened I was COMPLETLY lost too.