My wife's newish D7100 doesn't lock between the A and M modes, the modes she uses the most. The camera is about 8 months old and she is a reasonably careful shooter and I don't think she would ever force the dial to turn without unlocking it first. It has not been dropped. Obviously, this is dissapointing because it can now easily shift out of a mode.
I bought this at B&H along with the additional "drop and spill" warranty for her. Is this a warranty repair? Of course, I can always ask B&H about it too. And I do have an old D90 to use during a repair time. Any suggestions?