you may need to add the hooks needed by those plugins manually to your header.php(theme file) or it could be possible that your themes functions are overriding the meta tags that those plugins would be trying to add.
Also you could accomplish the same thing with a robots.txt file. You currently have a robots.txt file on your site that looks like this:
User-agent: *
Disallow: /wp-admin/
Disallow: /wp-includes/
you can add more rules into this file, for example:
to block indexing on:
http://www.smarthunts.com/charitable/locate-donate
add the following line to your robots.txt file:
Disallow: /charitable/locate-donate