I got a refurbished d3000 that came with the 18-70 lens and the camera worked perfectly. The lens just recently started messing up. When using autofocus with any option you can think of, it will focus in to the subject then back out and it will stop when the subject is blurry. It will keep on toggling and I'm unable to take a shot most of the time, if it does happen to capture its usually blurry.. I can't figure out why it does this now and I tried changing some of my options but nothing has helped. My friend put it on his nikon and it did the same thing, and I used his lens and it worked fine so I know its just the lens.