I recently bought a D600 and when I tried to tether it to my desktop running Win 7 and Lightroom 5.6, it doesn't 'see' the camera, although it shows up in Windows Explorer. I first tried it on my laptop also with Win 7 and Lr 5.6 and it recognized the D600 for a while and transfered files fine, then it stopped. Tried it again later after several pc and camera restarts and it did the same thing. I have a big portrait job tomorrow and am desperate. Thanks.