Call to the Drupal Gurus: The Hunt for the Rogue "</div>"

Like a superhero, you respond to the call of the moon-blue Drupal logo gleaming in the night sky above Gotham. Another chance to use your hard-won expertise in the service of others. The Commissioner directs you to a young man, a relative Drupal Newbie, who is mildly distressed.

The Scene
Drupal 4.6. A tableless CSS theme. A website, being developed for an academic journal, using the Tagnode module, along with Flexinode, to create an Issue-Article structure.

The Problem
You ask the Drupal newbie what went down. "The theme development was going well," he stammers, "and the test site was outputting valid XHTML. The layout looked great. I had a few different flexinode types set up, and some custom blocks. But I was still searching for way to handle the Issue-Article relationship because Taxonomy alone didn't quite do it for me. That's when I found Tagnode." You nod. "It was great," he continues. "It did everything I needed it to do, dynamically linking Issue nodes with Article nodes and making the content creation process easy for my colleagues. I was thrilled, really thrilled. But then I noticed that any nodes affected by tagnode were breaking my layout. They contained an extra </div> that severed my footer!"

"A severed footer," you think to yourself. "Not pretty."

"Well, I set about searching for the culprit. Figured it must have been in Tagnode. Even contacted Tagnode's author, Dado. But Tagnode only introduces four <div>s, and it closes each one of them. I re-checked my theme: everything properly nested, completely symmetrical. Here's the really interesting thing: no other page on my site was affected. Front page, fine. Other nodes, fine. Only the nodes affected by Tagnode have the extra </div>... but the module itself isn't where it's coming from! I thought maybe the problem was that I was building my theme with Smarty. So I ported the entire thing to PHP Template. Same problem."

An Inside Job?
"Is that all?" you ask.

"Well, I did notice one other thing. I'm not sure what it means. The Rogue </div> is appearing from within the <?php print($content) ?> call. I know this because it's inside of the <!-- begin content --> and <!-- end content --> comments, neither of which are in my theme files. I figure it must have to do with the combination of Tagnode with Flexinode, or something like that. But I'm reluctant change any other files, for fear that I'll screw up pages that work. I'm hoping it's just a theme question, but..." His voice trails off. You look up to find him staring into nowhere, looking confused. Suddenly, he looks back at you. "Where do you think it's coming from? What do you think I should do?"

You pause. Your mind scans years of drupalhero experiences as this sad-looking, distraught newbie waits for any sign of hope. Not wanting to let him down, you turn and say...