5.5 to 5.14 upgrade broke create/edit node's "accordion" functionality

Backstory: I upgraded from Drupal 5.5 to 5.14.

Observation: When I go to create a node (or go back to edit it), the various new node composition "accordion" panels are not even clickable, much less functional. (I don't know with certainty that this feature is referred to as "accordion" panels, so if I've described them incorrectly, please feel free to correct me.)

Specifically:

- XML sitemap settings
- URL path settings
- Comment settings
- Menu settings
- File attachments
- Authoring information
- Publishing options

Interestingly, when I try to copy/paste that part of the page to here, I get this:

URL path settings
Optionally specify an alternative URL by which this node can be accessed. For example, type "about" when writing an about page. Use a relative path and don't add a trailing slash or the URL alias won't work.
Comment settings
Disabled
Read only
Read/Write
Menu settings
Title:
The name to display for this menu link.
Description:
The description displayed when hovering over a menu item.
Parent item:
Weight:
Optional. In the menu, the heavier items will sink and the lighter items will be positioned nearer the top.
File attachments
Changes made to the attachments are not permanent until you save this post. The first "listed" file will be included in RSS feeds.
Attach new file:
XML Sitemap settings
Priority override:
Optionally override the site map priority for this post. The lowest priority is 0.0; the highest priority is 1.0. A priority of -1 will prevent this post from appearing in the site map.
Authoring information
Authored by:
Leave blank for Anonymous.
Authored on:
Format: 2008-12-23 21:08:55 -0600. Leave blank to use the time of form submission.
Publishing options

So it seems to have the stuff embedded, just incapable of displaying.

That said, I've got a boatload of modules reported which also apparently need updating. They seemed fine before the upgrade, and certainly posting new content wasn't having this issue prior to the upgrade.

I'm guessing one or more of these could be to blame, but I wouldn't mind getting someone's feedback first.