only able to comment on posts if there's already a comment

Hi All. We just upgraded a WordPress multisite test environment from 3.0.4 to 3.1.4. I just realized in testing out some of our plugins that visitors are unable to add a comment if there is no comment already. If there is a comment (as in the Hello World post), then the comment box appears.

I can see in the html that in the comments div there is a comments are closed tag, but given the settings that I’ve chosen (allowed comments on new articles, don’t have to be logged in to comment), it shouldn’t be there.

<div id=”comments”>
<p class=”nocomments”>Comments are closed.</p>

In the page with a comment already, the correct <div id = “resond”> is there.

I’ve already disabled all plugins to see if any of them were an issue. Any help would be greatly appreciated!