VW are being cautious and you can understand if you have experienced one break. Our '77 Golf LS was the first car we owned that had a timing belt and VW never gave any replacement interval that I can remember and we traded it at 165,000km with the original belt. A friend also had the same model Golf that finally boke its belt at just under 200,000km but with no damage. So VW certainly knew how to make long lasting belts then.