My initial response was meant to be helpful to the best of my ability and courteous, regardless, but apparently you didn't take it that way. So after this, I won't waste my time, but you comment that your 70-200 body/lens combo is focusing fine. From looking at the exif on 517, which indicates an FX focal length of 155mm, I'm guessing that's the lens you used for that shot. Which, if that's the case, apparently is not fine. You also refer me to a different photo (1393) that is in focus. I'm willing to bet that that photo was not taken at f2.8 - there is a great deal more depth-of-field in that image than in 517 and it was taken from farther away, which means you could have a back focus problem but it would be less obvious. However, since you are convinced you do not have a back focus problem even though you've never checked and seem reluctant to consider any of the suggestions you asked for from me or the other posters, then I guess you are on your own.