When signed in with an OpenID, the following error was being displayed at the bottom of the post page:
PHP Fatal error: Call to a member function query() on a non-object in /blog/wp-content/plugins/openid/comments.php on line 182
There was a missing
isset($wp_scripts). The code sample below includes my fix and corrects a typo in your comment :P
Is there perhaps a more serious problem, in that $wp_scripts isn't set?