I have been having problems with the auto focus on my lens. The focus doesn't seem to hold. It hunts forever before it locks on. When it finally does, it doesn't always hold. I'll wait for the focus, and then it'll get it, and then when I take the picture it will lose it and I get a blurry shot. I figured it was operator error at first, but it happens on the tripod with the cable release, too. Manual focus doesn't have the same problem. Which is fine for me, but I am not the only one who has to use the camera. Has anyone else experienced this? Or even understand what I am talking about?