Windoze 7 may not like the post box...............
A pic would help.Sounds like the clear is dying back in that spot. Did the bubbles come back?Some of the older clears are very difficult to buff after they've been on the car for years. I remember a car I painted in the 80s using 2020 clear and made the mistake of waiting 30 days to buff it. I never did get it as nice as I would have liked. Even modern clears are easier to buff soon after they are applied.