Three people have now moaned at me about my permalinks not working. "Huh?", thought I, "they do work. I spent a while testing everything to check that." And then I tried them and they didn't. Cursing and swearing, I realised that it wasn't Vellum's fault at all. You see, the archived posts all live in a directory called days, but I don't want people who go to http://www.kryogenix.org/days/ to see a simple index of my posts; instead, I want them to go to the front page and see that instead. So, I added a redirect directive or two to my days/.htaccess file, which is where configuration directives for my webserver (Apache) go. It looked like this:
Redirect /days/ http://www.kryogenix.org/
Redirect /days http://www.kryogenix.org/
Spot the deliberate mistake? Those /days/ and /days bits should have $ on the end of them, otherwise Apache remaps /days/1234.html to http://www.kryogenix.org/1234.html. And that's why my permalinks didn't work. Of course, after I added the Redirect directives, I didn't retest it. Let this be a lesson.