Has quit ringing?
I have the same problem as Sara had a a week or two and everything works fine even the settings and volume are correct, but no sound when an incoming call is received. The volume is up and all sound settings are correct.
I also have a Samsung Galaxy Centura, which I got a week or two ago. It has been receiving calls just fine, but all of a sudden today when people call me all it does is vibrate. I have checked all of the settings and can't find anything wrong with the sound, but it still won't ring.
Awesome David that fixed it!!!!! Thank you so much I was about to throw it in the drawer and get a new one.