Good to hear that I am not alone in this. Static noise (buzzing sound) happened when I switched to T-Mobile signal. While roaming to AT&T, calls were crystal clear. Since January 2010. there is no roaming agreement between T-Mobile and AT&T and I am stuck with T-Mobile's "buzz" signal. I took the phone apart, checked connections, put everything back - still static noise present but improved WiFi significantly. I am getting new sim-card from T-Mobile and let's see if it helps. Looks like the problem is with providers signal or antenna's reception.