Comments Half-Missing in 2.0 Upgrade

I hope I can explain this clearly, and I apologise in advance for the amount of illustrative code I’m about to post!

I’ve upgraded from 1.2 to 2.0 — most things are working fine. I’m using a custom template that’s all in one index.php file. My other two are comments.php and comments-popup.php.

I’ve got comments set to pop up, and that works fine, just like it did in the old install. Everything seems to have made the transition.

When I view a single post, though, the comments do not appear below it, like they used to. On the page, things chop off at the bottom of the post: “Filed under CategoryName | ” (After the | is where the % Comments line would appear.)

Here’s what’s going on in the code, in case that might help to clarify matters. In index.php, the chunk in question looks like this:

<div class="feedback">
[WP category code snipped!] | <?php comments_popup_link('Add your comment!','1 comment','% comments','comment','Comments (off)'); ?>
</div>
<?php trackback_rdf(); ?>
<?php comments_template(); ?>
</div><!-- end post div -->

It seems to be picking up the trackback_rdf() line ok — in an actual page, the code becomes:

<div class="feedback">
Filed under: [WP category stuff snipped!] | <a href="http://ferrellweb.com/wp/?comments_popup=109" title="[Title snipped!]">Add your comment!</a></div>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
[Etc. - trackback snipped!]
</rdf:RDF></div>

So it looks like to me that comments_template() isn’t processing, or is coming up blank. Does *anybody* have a clue how I can get this working again?

Thanks!
Jeff.
(Oh — the site’s at http://www.ferrellweb.com/wp right now, if looking helps any!)