diff -u menu_block.admin.inc menu_block.admin.inc
--- menu_block.admin.inc	2010-08-31 03:58:19.000000000 +0000
+++ menu_block.admin.inc	2010-09-10 04:58:06.000000000 +0000
@@ -41,6 +41,7 @@
   }
 
   drupal_set_message(t('The block has been created.'));
+  menu_block_get_delta(0,TRUE);
   cache_clear_all();
 
   $form_state['redirect'] = 'admin/build/block';
@@ -90,6 +91,7 @@
   db_query("DELETE FROM {blocks} WHERE module = 'menu_block' AND delta = %d", $delta);
   db_query("DELETE FROM {blocks_roles} WHERE module = 'menu_block' AND delta = %d", $delta);
   drupal_set_message(t('The "%name" block has been removed.', array('%name' => $form_state['values']['block_title'])));
+  menu_block_get_delta(0,TRUE);
   cache_clear_all();
   $form_state['redirect'] = 'admin/build/block';
   return;
diff -u menu_block.module menu_block.module
--- menu_block.module	2010-08-31 16:12:51.000000000 +0000
+++ menu_block.module	2010-09-10 05:22:12.000000000 +0000
@@ -218,34 +218,44 @@
 }
 
 /**
+ * Return block delta given global block ID.
+ *
+ * @param $bid
+ *   integer Global block ID from core Block module.
+ * @param $reset
+ *   Boolean Clear function's static cache and return empty result.
+ *
+ * @return
+ *   integer Block delta relative to menu_block.
+ */
+function menu_block_get_delta($bid,$reset=FALSE) {
+  static $blocks = array();
+  if ($reset) {
+    $blocks = array();
+    return $blocks;
+  }
+  if (!array_key_exists($bid,$blocks)) {
+    $block = db_fetch_array(db_query("SELECT module, delta FROM {blocks} WHERE bid = %d", $bid));
+    $blocks[$bid] = $block;
+  }
+  $delta = 0;
+  $block = $blocks[$bid];
+  if ($block && ($block['module'] == "menu_block")) {
+    $delta = $block['delta'];
+  }
+  return $delta;
+}
+
+/**
  * Build a menu tree based on the provided configuration.
  *
  * @param $config
- *   array An array of configuration options that specifies how to build the
- *   menu tree and its title.
- *   - delta: (string) The menu_block's block delta.
- *   - menu_name: (string) The machine name of the requested menu. Can also be
- *     set to MENU_TREE__CURRENT_PAGE_MENU to use the menu selected by the page.
- *   - parent_mlid: (int) The mlid of the item that should root the tree. Use 0
- *     to use the menu's root.
- *   - title_link: (boolean) Specifies if the title should be rendered as a link
- *     or a simple string.
- *   - admin_title: (string) An optional title to uniquely identify the block on
- *     the administer blocks page.
- *   - class_name: (string) An optional additional class name for the menu
- *   - level: (int) The starting level of the tree.
- *   - follow: (string) Specifies if the starting level should follow the
- *     active menu item. Should be set to 0, 'active' or 'child'.
- *   - depth: (int) The maximum depth the tree should contain, relative to the
- *     starting level.
- *   - expanded: (boolean) Specifies if the entire tree be expanded or not.
- *   - sort: (boolean) Specifies if the tree should be sorted with the active
- *     trail at the top of the tree.
+ *   Block configuration. See menu_tree_build() for details.
+ *
  * @return
- *   array An array containing the rendered tree in the 'content' key and the
- *   rendered title in the 'subject' key.
+ *   See menu_tree_page_data() for a description of the data structure.
  */
-function menu_tree_build($config) {
+function menu_block_tree_build($config) {
   // Retrieve the active menu item from the database.
   if ($config['menu_name'] == MENU_TREE__CURRENT_PAGE_MENU) {
     // Retrieve the list of available menus.
@@ -327,6 +337,42 @@
     menu_tree_sort_active_path($tree);
   }
 
+  return $tree;
+}
+
+/**
+ * Build and render a menu tree based on the provided configuration.
+ *
+ * @param $config
+ *   array An array of configuration options that specifies how to build the
+ *   menu tree and its title.
+ *   - delta: (string) The menu_block's block delta.
+ *   - menu_name: (string) The machine name of the requested menu. Can also be
+ *     set to MENU_TREE__CURRENT_PAGE_MENU to use the menu selected by the page.
+ *   - parent_mlid: (int) The mlid of the item that should root the tree. Use 0
+ *     to use the menu's root.
+ *   - title_link: (boolean) Specifies if the title should be rendered as a link
+ *     or a simple string.
+ *   - admin_title: (string) An optional title to uniquely identify the block on
+ *     the administer blocks page.
+ *   - class_name: (string) An optional additional class name for the menu
+ *   - level: (int) The starting level of the tree.
+ *   - follow: (string) Specifies if the starting level should follow the
+ *     active menu item. Should be set to 0, 'active' or 'child'.
+ *   - depth: (int) The maximum depth the tree should contain, relative to the
+ *     starting level.
+ *   - expanded: (boolean) Specifies if the entire tree be expanded or not.
+ *   - sort: (boolean) Specifies if the tree should be sorted with the active
+ *     trail at the top of the tree.
+ * @return
+ *   array An array containing the rendered tree in the 'content' key and the
+ *   rendered title in the 'subject' key.
+ */
+function menu_tree_build($config) {
+
+  // Build the tree
+  $tree = menu_block_tree_build($config);
+
   // Render the tree.
   $data = array();
   $data['subject'] = menu_block_get_title($config['title_link'], $config);