Since I'm seeing people double-posting because of the moderation lock, and so that I don't have to delete them in the comment queue, I have disabled pre-comment moderation for first posters for the time being.
Spamming will be deleted; anything that hits Akismet, hits the WordPress word list or has more than two hyperlinks in it will be held in the comment queue for moderation. If I get more spam, pre-comment moderation for first posters goes back on.
Hopefully, that won't be necessary!