I have a bold 9650 that changes the ringtones I set to vibrate or a single beep by itself. I check the settings and it is still on what I set it. When I go through the choices I get no sound or an error message. If I pull the battery it fixes the problem for a short time, maybe about a day but then it reverts to that problem. I have searched for this problem and found others with similar issues but short of pulling the battery all the time I can't find a solution. I haven't downloaded any apps excecpt crunch sms.