meta tags don't display when not authenticated
You have a patch for this issue. There is a README.txt file updated.

All you need to do is to render meta tags in your page--front.tpl.php, add following in this file of your theme:

&lt;?php
 render($page['content']['metatags']); 
?&gt;


Or you can try to add this in your template.php file of the theme:

&lt;?php
function THEMENAME_preprocess_page(&amp;$vars) {
  if (!empty($vars['is_front'])) {
    metatag_page_build($vars['page']);
  }
}
?&gt;


Just replace THEMENAME with the name of your theme.