Yeah, I'm more curious as to why Dropbox corrupted a few of my PDFs. Has been happening for years for a variety of people.
Also I should probably mention that we keep 1 month of version history for free users and even more history for paid users, so if the corruption is recent you should be able to undo it yourself. But please report either way.
(Full disclosure: I work for Dropbox).
I'll log a ticket :-) might need to reproduce the issue first. Pretty awesome that you have employees who respond to posts on HN incidentally, that automatically increases my loyalty to a company several notches!