I've had a couple of instances where my 70-200 VR just stops working on my D300. It will work great for about an hour and half, then the auto focus will just not work. I've compensated by switching to manual focus, but this is far from a prefect solution. I've tried turning the camera off, removing the lens, removing the battery, you name it. Has anyone else had this issue?

Common issue, easy fix. Clean the contacts on the lens and on the camera. You can use a pencil eraser. Just make sure you hold the lens (or camera) so the eraser junk falls to the floor and not into the lens (or camera).

Awesome, thanks! I'm going to try it now. I thought it might have something to do with cleaning the contacts. I just hope that's the issue.

Typically the batt signal comes up and it does not work. Make sure you clean the flange, the stainless steel ring on the camera too. This is a ground for the VR lenes and likely why no power is getting to the lens if there is a little dirt or oil there.