the following add will make ur menu link no visible if menu link it's empty and has no childs :

- file : admin.module
- function : admin_menu_navigation_links($tree, $admin_only = FALSE)
- modification

change

if (!$item['link']['hidden'] && (!$admin_only || !empty($item['link']['options']['admin']))) {

to

if (!$item['link']['hidden'] && ($item['below']) && (!$admin_only || !empty($item['link']['options']['admin']))) {