Ok so I noww have a freshly-restored iPhone 3GS 3.1.3. I restored it beacause the vibrate switch was messing up. Normally, when you switch it to silent, it will vibrate for a second, and when switched back to normal, it doesnt vibrate. My iPhone does the opposite. It vibrates when I put it on normal and does nothing on silent. It still sileneces the device, but its really bothering.