Let's be clear...99.9% of the phone works great. I was on build 9A404 (5.01 b2) up until this past Monday. I finally decided it was time to update my iPad 2 and iPhone 4S to build 9A405. Build 9A404 was working great. Since the update I am getting a ton of calls failed and dropped calls. Also the phone doesn't always register that a call is incoming and voicemails are delayed. But this only happens when I am in the house and my neighborhood. When I leave the general area (i.e switch to another tower), then the phone works perfectly. I tried a restore last night but it seems to still be an issue. Any idea why? Carrier is AT&T.