I have a Sigma 17-50 F/2.8 OS lens. I am very happy with this lens, works great for video. My question is for still photo. The lens only do auto focus if I turn the dial to auto mode. Auto focus will not work under creative mode ( P, TV mode example) If I use creative mode, I have to do manual focus. Can some one confirm this. Or this is a firm ware up date required. I appreciated any inputs.