I have the Zeiss 5x25x50mm HD5 and the parallex Dial felt like it was slipping. Had to adjust it to infinity image to focus at 100yds ? Callede Zeiss up they said send it ! Few days later when I was packaging the scope ,the Parallex dial seemed ok ? Sp I still sent it back saying I di8dn't want this to fail on the dream hunt . I wonder what's wrong ?