As Vic pointed out, my page ceased to be XHTML-compliant when I moved posts inside categories. Bloxsom generates an ID to use inside the name attribute of an tag in order to facilitate linking to individual posts. This is great except for posts in sub-categories, whose IDs are prepended with the path to that post. The forward-slash is not allowed inside a name attribute.

I was experiencing other problems with categories using the Blosxom script I stole from Sam Ruby, so it looks like I will have to drop categories for now. I would delve into the Blosxom code, but it’s icky Perl and I have enough trouble sleeping as it is. Perhaps I will take a second look at pyBlosxom and see if that’s any easier to modify. Unfortunately, I would lose all the niceties in Sam’s Blosxom script and it would probably be a little slower. We shall see.

Update: This issue has been fixed in a more recent version of Blosxom.