[Verdigo]

They get stuck because the plastic button is sitting on top of a sticky foam pad. Under that foam pad is a tiny pressure contact. sitting on top of that pressure contact is a small circular piece of plastic thats no bigger in diameter than the printed O on your O key. The button gets "Stuck" when the lil piece of plastic slides off the top of the contact. The only thing to push down the pressure contact is the backside of the sticky foam. Only way to fix this is to take the entire phone apart and reseat the plastic but that voids your warrenty.