diff -u -r1.15.2.4 book_access.module
--- book_access.module	21 Nov 2009 19:39:12 -0000	1.15.2.4
+++ book_access.module	22 Nov 2009 22:34:45 -0000
@@ -155,16 +155,20 @@
 /**
  * Implementation of hook_node_access_records().
  *
- * Returns a list of grant records for the passed in book node object. If we
- * have a book child page, we return the access settings of the top level parent.
+ * Returns a list of grant records for the book node object passed as argument.
+ * If we have a book child page, we return the access settings of the top level
+ * parent book page node.
  */
 function book_access_node_access_records($node) {
   $grants = array();
 
-  if (isset($node->book)) {
-    $book_nid = $node->book['bid'];
-
-    $result = db_query('SELECT * FROM {book_access} WHERE nid = %d', $book_nid);
+  if (($node->type == 'book') && isset($node->book['bid'])) {
+    $result = db_query('SELECT * FROM {book_access} WHERE nid = %d', $node->book['bid']);
 
     while ($grant = db_fetch_object($result)) {
       $grants[] = array(