Something else Gordon mentions in his review of the D7000 is back-focusing
Unfortunately though, all was not well with our D7000's focusing. Our initial test images looked a little soft, and upon further investigation, our sample kit was suffering from back-focusing.
Maybe you could follow his suggestion for fixing this to see if it helps your issue.
Nikon includes AF Fine Tune facilities which allow you to correct for front or back focusing on up to 12 lenses, and applying a value of -8 for the supplied kit lens greatly improved our results
Nikkor AF-S DX; 18-105 f/3.5-5.6G VR, 55-300 f/4.5-5.6G VR, 35mm f/1.8G
Speedlight SB-700 http://keystrokesukimages.com