I bought a Sigma 85 1.4 about 8 months ago and am looking for feedback from other users. It focuses fine at longer distances, but at or near the close focus limit it hunts continuously and will not autofocus. I have to switch to manual focus to shoot close subjects. Is this just a quirk of my copy or does this happen to others? I am using a 5D2, which I know is not the fastest focusing camera, but I have it locked on center focus point and this problem happens even with still subjects (and does not happen with any other lens).
Also, is this something Sigma would or could fix under warranty if I contact them? (I will likely try anyway, just wondering if anyone else has done this with success).