Index: wp-admin/admin-header.php
===================================================================
--- wp-admin/admin-header.php	(revision 4904)
+++ wp-admin/admin-header.php	(working copy)
@@ -29,15 +29,15 @@
 <?php if ( ($parent_file != 'link-manager.php') && ($parent_file != 'options-general.php') ) : ?>
 <style type="text/css">* html { overflow-x: hidden; }</style>
 <?php endif;
-if ( isset($page_hook) )
+if ( !empty($page_hook) )
 	do_action('admin_print_scripts-' . $page_hook);
-else if ( isset($plugin_page) )
+else if ( !empty($plugin_page) )
 	do_action('admin_print_scripts-' . $plugin_page);
 do_action('admin_print_scripts');
 
-if ( isset($page_hook) )
+if ( !empty($page_hook) )
 	do_action('admin_head-' . $page_hook);
-else if ( isset($plugin_page) )
+else if ( !empty($plugin_page) )
 	do_action('admin_head-' . $plugin_page);
 do_action('admin_head');
 ?>