Comments Trouble?

I received a disturbing email today from a regular reader who noticed his comments disappearing. He wondered, quite reasonably, why I was deleting them. This is disturbing because in over five years of blogging, I have never deleted a non-spam comment (definition of spam: touting a commercial product)--including his. Then this:

Huh. Read my message from a couple of minutes ago first, but: I just went back into the blog again and my most recent comment, which I thought had been successful, had disappeared, and the comment count, which was at 10 last time I checked, was back down to 9. Curiouser and Curiouser.

I have no idea what's going on, but if this has happened to you, email, will you? (Or try commenting, though that may be a Kafka-esque trap.) Uggh.