Yes this has happened to me as well. With the texts thats a given it always happens i know that. When it happens for me its when i receive a message from Facebook i get the tone ounce then as soon as i go check it happens again.
Personally im thinking of bringing my iPhone back to the store to get it changed. Been getting random freezes, my home button sometimes just stops working, my music goes low when playing it for no reason and jus random crashes of the phone