I had this lens for quite a few years now, it used to work as expected. I didn't use my stuff for a few months, maybe 6-8 months. I just bought a D600 and tried to use them. The AF does not work as it should: I need to move manually the AF ring, and then it goes. But it blocks at around 2m on the scale, and I have to move it again in order to focus.
I can focus manually. Same behaviour on the old body.