I hear something that I would normally mistake for the power button, but its VERY faint and I can't imagine shaking it like that during normal use. haha. I held the power button and volume rockers down all at once while shaking and i can still hear that faint noise... maybe the vibration piece doing it ? not sure what other 'moving parts' would make that noise.
My volume and power buttons do the same thing. It really sounds like this is happening more often than I had thought. I think the bar was set really high by my OG so I view this as annoying. As it's the only thing annoying me at the moment I'll ignore it until a button no longer responds then I'll deal with it under warranty.