Anyone else have this? I have had a time or two when my droid stopped responding right on the tough screen, so I turned the phone off to 'reboot' it. Upon powering the phone off, it makes a loud ringing sound. after waiting a minute or so to power the phone back on, it powers on fine, but does the loud ringing once more. Nonetheless, the 'reboot' seems to fix the problem the few times it's happened. This normal? Thanks!