It turns out that my comment engine was buggy, and I hadn’t noticed until just now. The bug was that if the first comment was spam, then no other comments were shown on that post. This has now been fixed. As an interesting side effect, the site now displays information about how many spammy comments I have seen on a given post. This is mostly interesting because it seems to me that some posts are being hit by the comment spammers much harder than others, and I’m not really sure why.