Index: modules/book/book.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/book/book.module,v
retrieving revision 1.483
diff -u -r1.483 book.module
--- modules/book/book.module	29 Dec 2008 16:03:56 -0000	1.483
+++ modules/book/book.module	17 Jan 2009 22:42:34 -0000
@@ -292,11 +292,14 @@
  *
  * This list may be used for generating a list of all the books, or for building
  * the options for a form select.
+ *
+ * @param $reset
+ *   Reset the cache of stored books.
  */
-function book_get_books() {
+function book_get_books($reset = FALSE) {
   static $all_books;
 
-  if (!isset($all_books)) {
+  if ($reset || !isset($all_books)) {
     $all_books = array();
     $nids = db_query("SELECT DISTINCT(bid) FROM {book}")->fetchCol();