I've had my Bionic for a couple weeks. After a couple days, it appeared to have lost its audible sound capability. No rings, no notifications. I've been setting up a lot of things, but I can't imagine how I might have turned it off. I've searched through the 'sounds' section of 'settings'. I've got sound turned on at the 'unlock' screen. Has anyone else had this problem? Does anyone know of any obscure, hidden ways you can turn sound off?