RSS link for comments

Hi,
I am using <?php comments_rss_link(‘RSS 2.0’); ?> in my single.php file as per the information provided here: http://codex.wordpress.org/WordPress_Feeds
my problem is that I am not seeing a link with each post to enable visitors to subscribe, even if I log out and then view the blog as a visitor.

I am wondering if there is something else needed to complete this objective, as if so, what that might be.
Thanks very much in advance for your help.