iPhone 5 power button rattles on vibrate My iPhone 5 has a slightly "loose" power button. Not like its going to fall off or anything, but it visibly wiggles a little bit, and if I stand the phone up and then quickly turn it upside down, or bump it, I can hear and see it move.

As this is my first iPhone, is this normal?

Just to clarify, it's not mushy, it just seems like the plastic "outer button" wiggles around on top of the actual button sensor inside. It certainly has a nice firm click when pressed.

Edit: certain vibrate patterns also make it rattle very fast, making a buzzing sound. If I put my finger lightly on it, it stops. 

Edit 2: macrumors is full of people with similar beefs. I'm guessing this isn't just me.
It sounds normal, if a bit looser than my 4S. If it concerns you, you might be able to get a replacement unit from an Apple Store, though there are no guarantees that it will have better buttons (when I replaced my iPhone 4 two years back for a different issue, the replacement I received had noticeably mushier buttons).