Actually this module seems to be abandoned. And the use of [drupal_add_library][1] woks only if the module used the hook_library and I wanted to check it in the repo of jquery_plugin but these files .module aren't available. I don't know why.

But if you want use overlay, you can use directly the jQuery UI that is already included in Drupal 7.


  [1]: http://api.drupal.org/api/drupal/includes--common.inc/function/drupal_add_library/7