Hi Eugene, Not long ago I got my D3 back from its third trip to Nikon to get it to autofocus reliably. It would autofocus most of the time but then would hang for a series of attempts -- always, of course, at the worst possible moment, then break loose and work again. Since it was an intermittent it was hard for the Nikon crew to replicate the problem. It was getting progressively worse though, and finally somebody there found spotted it, replaced some parts, and fixed it. It started out with a single hang that didn't repeat for some time, so keep watching. If it happens again you might want to send it in before it gets too bad.