diff -ruN original/menu_block/menu_block.follow.inc mod/menu_block/menu_block.follow.inc
--- original/menu_block/menu_block.follow.inc	2008-12-01 15:56:56.000000000 +0600
+++ mod/menu_block/menu_block.follow.inc	2009-11-10 23:09:13.000000000 +0600
@@ -52,6 +52,12 @@
         }
         // If the active menu item has no children, we're done.
         else {
+          //If we need children and active item doesn't have any, don't show siblings.
+          if ($level == 'child')
+          {
+            $menu_title = NULL;
+            $tree = array();
+          }
           break 2;
         }
       }