Ah-ha. I think I found the cause. Turns out the search form in the sidebar was overriding the form settings in the comments form. Here’s the fubaring code from the sidebar:
<form id=”searchform” method=”get” action=”<?php bloginfo(‘home’); ?>”>
<p><input type=”text” name=”s” id=”s” size=”15″ />
<input type=”submit” value=”<?php _e(‘Search’); ?>” />
I killed it dead, and now the comments will actually post. Yay!
Yup, comments are enabled, both in the settings and on the latest post. (Comments are closed after 30 days.)
