I just discovered that the old WordPress-hosted site is still sending out emails and RSS feeds. Therefore, I’m getting comments at both the old and new site. I’ve figured out how to keep the old site from posting new posts — which should fix that. I’ve also blocked new comments on the old site.
TheoBloggers should now be sending out both RSS feeds and emails, full text and in HTML (pictures and formatting). Please let me know if there are any other problems with the conversion.