diff --git a/includes/menu.inc b/includes/menu.inc
index 2be0903..9a416ec 100644
--- a/includes/menu.inc
+++ b/includes/menu.inc
@@ -391,14 +391,27 @@ function menu_get_ancestors($parts) {
  *   A path argument array, used to replace integer values in $data; an integer
  *   value N in $data will be replaced by value $map[N]. Typically, the $map
  *   array is generated from a call to the arg() function.
+ * @param $item
+ *   A menu router or menu link item.
+ *   Contains all data to dynamically load a corresponding object (entity).
+ *   $item['access'] may be set to FALSE, when the object cannot be loaded.
  *
  * @return
- *   The unserialized $data array, with path arguments replaced.
+ *   The unserialized $data array, with path arguments replaced,
+ *   or FALSE, if an error occurred loading an object.
  */
-function menu_unserialize($data, $map) {
+function menu_unserialize($data, $map, $item) {
   if ($data = unserialize($data)) {
     foreach ($data as $k => $v) {
       if (is_int($v)) {
+        // Load the object for the given id.
+        if (!empty($item['load_functions']) && !_menu_load_objects($item, $map)) {
+          // An error occurred loading an object.
+          // Do not set access to FALSE: results in unwanted 404-error
+          // on non-existing page, like content/123.
+          $item['access'] = FALSE; // This is already done in _menu_load_objects()
+          return FALSE;
+        }
         $data[$k] = isset($map[$v]) ? $map[$v] : '';
       }
     }
@@ -417,9 +430,9 @@ function menu_unserialize($data, $map) {
  * @param $path
  *   The path.
  * @param $router_item
- *   The router item. Usually a router entry from menu_get_item() is either
- *   modified or set to a different path. This allows the navigation block,
- *   the page title, the breadcrumb, and the page help to be modified in one
+ *   The router item. Usually you take a router entry from menu_get_item and
+ *   set it back either modified or to a different path. This lets you modify the
+ *   navigation block, the page title, the breadcrumb and the page help in one
  *   call.
  */
 function menu_set_item($path, $router_item) {
@@ -427,7 +440,7 @@ function menu_set_item($path, $router_item) {
 }
 
 /**
- * Gets a router item.
+ * Get a router item.
  *
  * @param $path
  *   The path, for example node/5. The function will find the corresponding
@@ -436,13 +449,12 @@ function menu_set_item($path, $router_item) {
  *   Internal use only.
  *
  * @return
- *   The router item or, if an error occurs in _menu_translate(), FALSE. A
- *   router item is an associative array corresponding to one row in the
- *   menu_router table. The value corresponding to the key 'map' holds the
- *   loaded objects. The value corresponding to the key 'access' is TRUE if the
- *   current user can access this page. The values corresponding to the keys
- *   'title', 'page_arguments', 'access_arguments', and 'theme_arguments' will
- *   be filled in based on the database values and the objects loaded.
+ *   The router item, an associate array corresponding to one row in the
+ *   menu_router table. The value of key map holds the loaded objects. The
+ *   value of key access is TRUE if the current user can access this page.
+ *   The values for key title, page_arguments, access_arguments, and
+ *   theme_arguments will be filled in based on the database values and the
+ *   objects loaded.
  */
 function menu_get_item($path = NULL, $router_item = NULL) {
   $router_items = &drupal_static(__FUNCTION__);
@@ -477,8 +489,8 @@ function menu_get_item($path = NULL, $router_item = NULL) {
       }
       if ($router_item['access']) {
         $router_item['map'] = $map;
-        $router_item['page_arguments'] = array_merge(menu_unserialize($router_item['page_arguments'], $map), array_slice($map, $router_item['number_parts']));
-        $router_item['theme_arguments'] = array_merge(menu_unserialize($router_item['theme_arguments'], $map), array_slice($map, $router_item['number_parts']));
+        $router_item['page_arguments'] = array_merge(menu_unserialize($router_item['page_arguments'], $map, $router_item), array_slice($map, $router_item['number_parts']));
+        $router_item['theme_arguments'] = array_merge(menu_unserialize($router_item['theme_arguments'], $map, $router_item), array_slice($map, $router_item['number_parts']));
       }
     }
     $router_items[$path] = $router_item;
@@ -557,6 +569,22 @@ function _menu_load_objects(&$item, &$map) {
     if (!is_array($load_functions)) {
       $load_functions = unserialize($load_functions);
     }
+
+    // If the object is loaded before, don't load it again.
+    if (isset($item['_object_map'])) {
+      if ($item['_object_map'] === FALSE) {
+          $item['access'] = FALSE;
+          $item['_object_map'] = FALSE;
+          $map = FALSE;
+          return FALSE;
+      }
+      else {
+        $map = $item['_object_map'];
+        return TRUE;
+      }
+    }
+    $item['_object_map'] = array();
+
     $path_map = $map;
     foreach ($load_functions as $index => $function) {
       if ($function) {
@@ -595,6 +623,7 @@ function _menu_load_objects(&$item, &$map) {
         // If callback returned an error or there is no callback, trigger 404.
         if ($return === FALSE) {
           $item['access'] = FALSE;
+          $item['_object_map'] = FALSE;
           $map = FALSE;
           return FALSE;
         }
@@ -602,12 +631,13 @@ function _menu_load_objects(&$item, &$map) {
       }
     }
     $item['load_functions'] = $load_functions;
+    $item['_object_map'] = $map;
   }
   return TRUE;
 }
 
 /**
- * Checks access to a menu item using the access callback.
+ * Check access to a menu item using the access callback
  *
  * @param $item
  *   A menu router or menu link item
@@ -615,10 +645,15 @@ function _menu_load_objects(&$item, &$map) {
  *   An array of path arguments (ex: array('node', '5'))
  *
  * @return
+ *   TRUE if the object-at-hand could be loaded, FALSE otherwise.
  *   $item['access'] becomes TRUE if the item is accessible, FALSE otherwise.
  */
 function _menu_check_access(&$item, $map) {
-  $item['access'] = FALSE;
+  // menu_tree_check_access() may set this ahead of time for links to nodes.
+  if (isset($item['access'])) {
+    return TRUE;
+  }
+
   // Determine access callback, which will decide whether or not the current
   // user has access to this path.
   $callback = empty($item['access_callback']) ? 0 : trim($item['access_callback']);
@@ -627,7 +662,12 @@ function _menu_check_access(&$item, $map) {
     $item['access'] = (bool) $callback;
   }
   else {
-    $arguments = menu_unserialize($item['access_arguments'], $map);
+    $arguments = menu_unserialize($item['access_arguments'], $map, $item);
+    if ($arguments === FALSE) {
+      // An error happened when loading the object. $item['access'] is now set to FALSE.
+      return FALSE;
+    }
+
     // As call_user_func_array is quite slow and user_access is a very common
     // callback, it is worth making a special case for it.
     if ($callback == 'user_access') {
@@ -637,10 +677,11 @@ function _menu_check_access(&$item, $map) {
       $item['access'] = call_user_func_array($callback, $arguments);
     }
   }
+  return TRUE;
 }
 
 /**
- * Localizes the router item title using t() or another callback.
+ * Localize the router item title using t() or another callback.
  *
  * Translate the title and description to allow storage of English title
  * strings in the database, yet display of them in the language required
@@ -683,6 +724,11 @@ function _menu_item_localize(&$item, $map, $link_translate = FALSE) {
   // If we are translating a router item (tabs, page, breadcrumb), then we
   // can always use the information from the router item.
   if (!$link_translate || ($item['title'] == $item['link_title'])) {
+    $title_arguments = menu_unserialize($item['title_arguments'], $map, $item);
+    if ($title_arguments === FALSE) {
+      // An error happened when loading the object. $item['access'] is now set to FALSE.
+      return;
+    }
     // t() is a special case. Since it is used very close to all the time,
     // we handle it directly instead of using indirect, slower methods.
     if ($callback == 't') {
@@ -690,7 +736,7 @@ function _menu_item_localize(&$item, $map, $link_translate = FALSE) {
         $item['title'] = t($item['title']);
       }
       else {
-        $item['title'] = t($item['title'], menu_unserialize($item['title_arguments'], $map));
+        $item['title'] = t($item['title'], $title_arguments);
       }
     }
     elseif ($callback && function_exists($callback)) {
@@ -698,7 +744,7 @@ function _menu_item_localize(&$item, $map, $link_translate = FALSE) {
         $item['title'] = $callback($item['title']);
       }
       else {
-        $item['title'] = call_user_func_array($callback, menu_unserialize($item['title_arguments'], $map));
+        $item['title'] = call_user_func_array($callback, $title_arguments);
       }
       // Avoid calling check_plain again on l() function.
       if ($callback == 'check_plain') {
@@ -748,7 +794,7 @@ function _menu_item_localize(&$item, $map, $link_translate = FALSE) {
  *   $item['load_functions']. $item['access'] becomes TRUE if the item is
  *   accessible, FALSE otherwise. $item['href'] is set according to the map.
  *   If an error occurs during calling the load_functions (like trying to load
- *   a non-existent node) then this function returns FALSE.
+ *   a non existing node) then this function return FALSE.
  */
 function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
   if ($to_arg && !empty($router_item['to_arg_functions'])) {
@@ -758,11 +804,6 @@ function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
   // The $path_map saves the pieces of the path as strings, while elements in
   // $map may be replaced with loaded objects.
   $path_map = $map;
-  if (!empty($router_item['load_functions']) && !_menu_load_objects($router_item, $map)) {
-    // An error occurred loading an object.
-    $router_item['access'] = FALSE;
-    return FALSE;
-  }
 
   // Generate the link path for the page request or local tasks.
   $link_map = explode('/', $router_item['path']);
@@ -773,6 +814,12 @@ function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
     $tab_parent_map = explode('/', $router_item['tab_parent']);
   }
   for ($i = 0; $i < $router_item['number_parts']; $i++) {
+    // data may not be aligned, like menu_router item 'node/%/edit/add/%/%'.
+    if (!isset($path_map[$i])) {
+//      dpm(debug_backtrace());
+//      continue;
+    }
+
     if ($link_map[$i] == '%') {
       $link_map[$i] = $path_map[$i];
     }
@@ -787,7 +834,13 @@ function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
   $router_item['tab_root_href'] = implode('/', $tab_root_map);
   $router_item['tab_parent_href'] = implode('/', $tab_parent_map);
   $router_item['options'] = array();
-  _menu_check_access($router_item, $map);
+
+  if (!_menu_check_access($router_item, $map)) {
+  //if (isset ($router_item['_object_map']) && $router_item['_object_map'] === FALSE) {
+    // The object could not be loaded.
+    $router_item['access'] = FALSE;
+    return FALSE;
+  }
 
   // For performance, don't localize an item the user can't access.
   if ($router_item['access']) {
@@ -798,14 +851,14 @@ function _menu_translate(&$router_item, $map, $to_arg = FALSE) {
 }
 
 /**
- * Translates the path elements in the map using any to_arg helper function.
+ * This function translates the path elements in the map using any to_arg
+ * helper function. These functions take an argument and return an object.
+ * See http://drupal.org/node/109153 for more information.
  *
  * @param $map
  *   An array of path arguments (ex: array('node', '5'))
  * @param $to_arg_functions
  *   An array of helper function (ex: array(2 => 'menu_tail_to_arg'))
- *
- * @see hook_menu()
  */
 function _menu_link_map_translate(&$map, $to_arg_functions) {
   $to_arg_functions = unserialize($to_arg_functions);
@@ -822,14 +875,14 @@ function _menu_link_map_translate(&$map, $to_arg_functions) {
 }
 
 /**
- * Returns a string containing the path relative to the current index.
+ * Returns path as one string from the argument we are currently at.
  */
 function menu_tail_to_arg($arg, $map, $index) {
   return implode('/', array_slice($map, $index));
 }
 
 /**
- * Loads the path as one string relative to the current index.
+ * Loads path as one string from the argument we are currently at.
  *
  * To use this load function, you must specify the load arguments
  * in the router item as:
@@ -846,10 +899,8 @@ function menu_tail_load($arg, &$map, $index) {
 }
 
 /**
- * Provides menu link access control, translation, and argument handling.
- *
- * This function is similar to _menu_translate(), but it also does
- * link-specific preparation (such as always calling to_arg() functions).
+ * This function is similar to _menu_translate() but does link-specific
+ * preparation such as always calling to_arg functions
  *
  * @param $item
  *   A menu link.
@@ -917,15 +968,12 @@ function _menu_link_translate(&$item, $translate = FALSE) {
       $item['access'] = FALSE;
       return FALSE;
     }
-    // menu_tree_check_access() may set this ahead of time for links to nodes.
-    if (!isset($item['access'])) {
-      if (!empty($item['load_functions']) && !_menu_load_objects($item, $map)) {
-        // An error occurred loading an object.
-        $item['access'] = FALSE;
-        return FALSE;
-      }
-      _menu_check_access($item, $map);
+    if (!_menu_check_access($item, $map)) {
+      // The object could not be loaded.
+      $item['access'] = FALSE;
+      return FALSE;
     }
+
     // For performance, don't localize a link the user can't access.
     if ($item['access']) {
       _menu_item_localize($item, $map, TRUE);
@@ -943,7 +991,7 @@ function _menu_link_translate(&$item, $translate = FALSE) {
 }
 
 /**
- * Gets a loaded object from a router item.
+ * Get a loaded object from a router item.
  *
  * menu_get_object() provides access to objects loaded by the current router
  * item. For example, on the page node/%node, the router loads the %node object,
@@ -971,7 +1019,10 @@ function _menu_link_translate(&$item, $translate = FALSE) {
 function menu_get_object($type = 'node', $position = 1, $path = NULL) {
   $router_item = menu_get_item($path);
   if (isset($router_item['load_functions'][$position]) && !empty($router_item['map'][$position]) && $router_item['load_functions'][$position] == $type . '_load') {
-    return $router_item['map'][$position];
+    $map = $router_item['map'];
+    if (_menu_load_objects($router_item, $map)) {
+      return $map[$position];
+    }
   }
 }