Although not a serious issue, I've noticed something while playing with my phone. If I play around with my keyboard (mash a bunch of buttons at once) while the the screen is off, I can somehow manage to produce a vibration. This happens like randomly. Sometimes I can't get it to do it; other times I can get it to do it like crazy. Anybody else notice this glitch? It's kind of annoying because it makes me feel like my phone is defective.