At this risk of further revealing what an ***** I am, I missed a couple calls and for the life of me couldn't figure out why the phone wouldn't ring, checked the sounds multiple times. Then realized that when on today screen, the volume buttons adjust the ringer volume and all the way down=off, in fiddling around without looking or something, I had moved the volume all the way down to off. Seems that my wife's 650 required you to push the extra side button to confirm a change in volume to protect against this sort of thing, but perhaps my recall is off. In any event: 1) be careful; and 2) if there is some sort of fix for this, I'd love to know it. I know the buttons don't work when the keyguard is on, but I guess I have a habit of pressing them from back in my i600 days when a press on the volume button would turn on the backlight to read the clock.