latest zen theme make the admin drop menu failed to work
Is it possible you've confused the Drupal 7 "Toolbar" module (which is enabled by default on D7) with the behaviour of the familiar "Admin Menu" module?

If so, then you can get the behaviour you want by


Install Admin Menu module
Visit your modules page and disable "Toolbar", then enable "Admin Menu" (and if you like, "Admin Menu Toolbar"


Or, with Drush -

drush dl admin_menu &amp;&amp; drush -y dis toolbar &amp;&amp; drush -y en admin_menu_toolbar


(Enabling Admin Menu Toolbar style implicitly enables Admin Menu also.)