WordPress automatically makes any link nofollow except the comment author. I have checked the comment-template.php but it seems to be fine:
function get_comment_author_link() {
/** @todo Only call these functions when they are needed. Include in if... else blocks */
$url = get_comment_author_url();
$author = get_comment_author();
if ( empty( $url ) || 'http://' == $url )
$return = $author;
else
$return = "<a href='$url' rel='external nofollow' class='url'>$author</a>";
return apply_filters('get_comment_author_link', $return);
}
Is there anywhere else I could look?