Originally posted by gebco K-x doesn't have auto ISO in manual mode.
Beleive me, you do not want auto ISO in this situation, all that will do is cause your exposures to be all over the place and mostly to blow highlights badly.
Use manual mode, pick an ISO (say 3200, 4000, 5000 or 6400), shoot wide open, and hopefully you will get the shutter speed you need for good exposure. If not, adjust ISO.
I would also advise turning on blinkies and using them to detect whether you have the highlights you want to keep. Even a histogram is not much use as you know you will blow any lights in shot, but you absolutely don't want to blow faces. A histogram can't show you that, highlight blinkies can though. Usually I don't like blinkies, too distracting, but in this case they are useful so you know exactly which elements of your photo you have within the DR of the camera.