Again, many thanks to Darrell Norton for telling me that my new content rating system didn’t work.
It turns out that the problem wasn’t with the content rating system but with my dasBlog2DotText content conversion tool. I didn’t escape the ‘<’ and ‘>’ characters when I moved them from dasBlog to .TEXT. I’m guessing that dasBlog did that on the way out while .TEXT does it on the way in… not sure.
Regardless, once I fixed the content in that article (and a few others) the whole thing started working again.