The D800 Fix: some pragmatic thoughts

Your point about the different AF capabilities depending on the type of light used is really pretty interesting. I have noticed something similar.

When Im shooting with my SB 700 flash, I will have a very obvious (like LCD obvious) problem with back focus on the left AF points. But then when I sit down to really test the camera, which I only do under bright sunlight to isolate as many factors as possible, the problem disappears. Its actually been very frustrating, as my 'real' shots definitely show a problem, but the testing I perform seems to be unable to find it.

One question I have though, is why would using the flash necessarily make the left AF points worse, without impacting the center?