It's pretty weird... I have the profile set for "Loudest" and the phone NEVER rings. However, I can still use the speakerphone and walkie talkie feature of the phone. I just can't get the damn thing to ring! It does vibrate on an incoming call/message however.
Edit: if I try to play a tune using the "Show Tunes" nothing ever plays :(
And no, it's not muted