Yeah, I don't know what's up. I've toggled the little on/off switch down there by it from off to on to enabled, and nothing. This happened once before, and a friend fixed it for me, saying that someone had switched it off while in some other mode or something... Anyway, when in (M) manual mode, it won't control the aperture anymore. In fact, I can't control the aperture in that mode at all anymore! Please help!