I have a 17-85MM Canon USM lens. Recently, it cannot autofocus. The lens cannot settle on a focus point just like an older photographer with poor eyes trying to focus a manual focus lens, which describes me at 52. I have cleaned the contacts, but the problem persists. My other lenses work fine on my XTi, so the camera body seems ok. Any ideas about the problem and the cost of the repair. I am getting nothing out of Canon, except send it in and we'll take a look. It seems like it could be a costly repair, which is very disappointing as I have only owned the lens for 2 years, used it moderately, have not dropped it, and have not gotten it wet. Thanks for any feedback that you my have.