I have never had a problem with auto-focus, except on some early digital P&S cameras that wouldn't auto-focus on anything in low light. I have a D200 and it auto-focuses beautifully. Mine has been set up for years, so I can't remember how I set it, but the key is this: You want AF-S (single auto focus, not continuous, i.e., when you press the shutter half-way down, it focuses and locks, until you release the shutter button.). You want a single small rectangle in the center of the frame to cover the auto-focus point. (I can't remember how to set that on the D200, but it's not hard.) To focus, you point the camera at your subject, let the little green rectangle cover the point you want to focus on, half-way press the shutter button, voila you are focused, all the time, every time.
I really don't understand the fuss about this issue.
/T