In what has become the most-replied-to message on my LJ to date, I have a mystery. A pair of comments, one of which I think was mine, have been deleted. The two deleted posts appear to be here -- not their text, of course, just the (deleted post) flag. I didn't delete them, and the person who made one of them claims he didn't delete them, either. So what could have caused them to vanish like that?