Aha.

Okay, so here’s a problem: the Tag Cloud on the main page is populated by actual tags, while the Squible show_tags() function on the single-post page shows cats as tags (since it only runs when wp_cats_as_tags is activated, duh). Sort that one out, why don’t you? This post, by the way, is in the “Asides (ID: 20)” category, but has tags “aside-tag1″ and “aside_tag2″.