Folks, Anyone else having problems with the volume control not working? The volume icon on the menu bar is greyed out, and pressing the F10/F11/F12 buttons don't adjust the volume. BUT the sound still works, but is stuck at full volume. It was working for a few days after upgrade, but now it's not. I've rebooted a few times, but still lots of sound and no volume control. Any clues? It's on a MacBook Pro 13" Mid09 model (2.53GHz, 4GB).