I’m afraid I’ve made a bad mistake and deleted not just a nutty spam comment, but the entire “blogback” account comment file, meaning that unless the fellow who runs “blogback” has a backup, any comments after early June or so are gone. Argh. I value (almost) everyone’s comments, and I’m very sorry about this. Serves me right, I suppose.
In case there is a backup, I think any new messages might complicate the process of restoring them. Also, the “blogback” system I’ve been using was going offline soon anyway. I’m temporarily deactivating it altogether while it while I look for a replacement service that I like and that I can import my old comment XML file into. You can reach me by e-mail  if there’s something you want to tell me.
UPDATE, 9/8: no backup at “blogback.” In the scheme of things, this is a small loss, but I feel it, and I apologize to all of you who’ve commented here over the last few months.