Hi
I sold my 105vr because the focus hunting drove me mad, even on a D3. I even sent it to Nikon to have it checked over and they said it was within tolerances. Quite often it would just completely stop focusing and would need some manual override. This is not an uncommon issue, I believe, and is probably related to the the huge distance range that the focusing mechanism has to cover to function in macro. I replaced it with a 2nd hand 85mm 1.4 and have never regretted it (I am not interested in macro photography.
I think Uncle Ken Rockwell reported a similar problem with the first one he tried but reports that later models seemed to focus better. Perhaps I had a duff one.
Hope this helps