diff --git modules/system/system.admin.inc modules/system/system.admin.inc
index c10a290..176780c 100644
--- modules/system/system.admin.inc
+++ modules/system/system.admin.inc
@@ -44,9 +44,11 @@ function system_main_admin_page($arg = NULL) {
       if ($item['block_callback'] && function_exists($item['block_callback'])) {
         $function = $item['block_callback'];
         $block['content'] .= $function();
+        $block['show'] = TRUE;
       }
       $content = system_admin_menu_block($item);
-      if ((isset($item['page_callback']) && !in_array($item['page_callback'], array('system_admin_menu_block_page', 'system_admin_config_page', 'system_settings_overview'))) || count($content)) {
+      $admin_block_callbacks = variable_get('system_admin_block_callbacks', array('system_admin_menu_block_page', 'system_admin_config_page', 'system_settings_overview'));
+      if ((isset($item['page_callback']) && !in_array($item['page_callback'], $admin_block_callbacks)) || count($content)) {
         // Only show blocks for items which are not containers, or those which
         // are containers and do have items we can show.
         $block['show'] = TRUE;
@@ -57,7 +59,9 @@ function system_main_admin_page($arg = NULL) {
       }
       // Prepare for sorting as in function _menu_tree_check_access().
       // The weight is offset so it is always positive, with a uniform 5-digits.
-      $blocks[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['mlid']] = $block;
+      if ($block['show']) {
+        $blocks[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['mlid']] = $block;
+      }
     }
   }
   if ($blocks) {
@@ -101,10 +105,14 @@ function system_admin_config_page() {
         $function = $item['block_callback'];
         $block['content'] .= $function();
       }
-      $block['content'] .= theme('admin_block_content', array('content' => system_admin_menu_block($item)));
-      // Prepare for sorting as in function _menu_tree_check_access().
-      // The weight is offset so it is always positive, with a uniform 5-digits.
-      $blocks[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['mlid']] = $block;
+      $content = system_admin_menu_block($item);
+      // A block with no content and no links is suppressed.
+      if ($content || $block['content']) {
+        $block['content'] .= theme('admin_block_content', array('content' => $content));
+        // Prepare for sorting as in function _menu_tree_check_access().
+        // The weight is offset so it is always positive, with a uniform 5-digits.
+        $blocks[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['mlid']] = $block;
+      }
     }
   }
   if ($blocks) {
diff --git modules/system/system.module modules/system/system.module
index 6c4fa3a..2b13495 100644
--- modules/system/system.module
+++ modules/system/system.module
@@ -1967,7 +1967,7 @@ function system_admin_menu_block($item) {
   if (isset($cache[$item['mlid']])) {
     return $cache[$item['mlid']];
   }
-
+  $admin_block_callbacks = variable_get('system_admin_block_callbacks', array('system_admin_menu_block_page', 'system_admin_config_page', 'system_settings_overview'));
   $content = array();
   $default_task = NULL;
   $has_subitems = FALSE;
@@ -1985,6 +1985,9 @@ function system_admin_menu_block($item) {
       $link['options'] = 'a:0:{}';
       $link['weight'] = $link['router_weight'];
     }
+    elseif (empty($link['has_children']) && in_array($item['page_callback'], $admin_block_callbacks)) {
+      continue;
+    }
     else {
       // We found a non-tab subitem, remember that.
       $has_subitems = TRUE;