LBP sound question

sometimes after playing LittleBigPlanet for a while, i go back to the pod and some sounds are gone, specifically the popping sound that should playing when scrolling through the menu or levels. it only happens in LBP and only this sound, all other sounds play fine. is that common?

id like to hope this isnt your problem but a while ago that happend to me and it turned out my data was corrupted it started like that and then the game just kept freezing you may have to delete your save but wait until it starts freezing to assume that because im probably wrong