My lens autofocus does not work in long distance (more than 6 meters)

I have a Nikon D70 camera and a Nikon AF 28-105mm f/3.5-4.5D. The autofocus works fine in 6 meters distance, but more than that, the autofocus will not lock and it will not also let me take any picture. For example, 10 meters away from the object, autofocus fails miserably but the manual focus still works. However, no matter how I set the focus, the picture seems to be out of focus. I have try different apertures but it does not help at all. When I try to take a landscape picture, it seems to be out of focus also (even if I set it to infinity).

Have you been turning the focus ring without changing the switch from AF to MF first?

Besides the aperture lock, you'll also find a Normal/Macro switch. Be sure the switch is set for Normal.

Sounds to me like the lens is broken. If you are operating it correctly and/or it used to work, contact Nikon to get an estimate on fixing it.
http://www.nikonusa.com/...epair.page