Does live view show backfocus probs?
can you qualify this answer - IF a photo taken with live view is out (back or front focus) does it indicate a prob with lens or camera or maybe both. How about manual focus in live view - as above .
Live view focuses directly off the sensor and can't back focus. It will be dead on. If you are getting back focusing using LV, it's probably the lens. An easy test is to simply try it with a different lens. If you can't get a correct focus using LV, send the camera in for repair.
BTW, make sure you're in bright light, parallel to the target at 50x the focal length of the lens. If you're not doing that, the test is invalid and needs to be redone.