Index: wp-admin/admin-footer.php
===================================================================
--- wp-admin/admin-footer.php	(revision 11653)
+++ wp-admin/admin-footer.php	(working copy)
@@ -25,7 +25,7 @@
 <?php
 do_action('admin_footer', '');
 do_action('admin_print_footer_scripts');
-do_action("admin_footer-$hook_suffix");
+if ( isset($hook_suffix)) {do_action("admin_footer-$hook_suffix");}
 
 // get_site_option() won't exist when auto upgrading from <= 2.7
 if ( function_exists('get_site_option') ) {