Repl-to Comments not nesting

I posted this in troubleshooting, but I haven’t gotten an answer so I thought I’d post it here:

When I reply to comments from the comments area in the admin section, I click “reply” under each comment, but it doesn’t appear nested under the original poster…Er, if this doesn’t make sense, please see here:

http://thecinnamonquill.com/blog/?p=323#comments

Do I need to implement the javascript described here?
http://ottodestruct.com/blog/2008/09/29/wordpress-27-comments-enhancements/

(eg add this: if ( is_singular() ) wp_enqueue_script( ‘comment-reply’ ); )

Thank you…!