Is there any way to lock the ringer volume? I keep my phone on vibrate always... well, I try to, but sometimes I hit the volume button on accident and it would be nice to not have to adjust it. Not only do I not want the phone to ring, but I don't want it to not vibrate (all the way down). Also, I still don't always understand when I can adjust other volumes, like Media Volume. Sometimes I start an app or music and the volume is too loud. It seems like sometimes I can't adjust the volume till after it starts playing.