--- booktree.module~	2009-10-23 19:09:10.000000000 -0400
+++ booktree.module	2010-11-01 10:29:34.000000000 -0400
@@ -121,8 +121,8 @@
   }
 
   $node = node_load(array('nid' => $booktree_start));
-  drupal_set_title(check_plain($node->title));
-  $content = '<p>'. check_markup($node->body, $node->format, FALSE) .'</p>';
+  drupal_set_title(check_plain($node->title?$node->title:variable_get('site_name', '')));
+  $content = '<p>'. check_markup($node->body?$node->body:"", $node->format, FALSE) .'</p>';
   $ricursione = 1;
   $content .= _booktree_mostra_figli($node->book['mlid'], $node->nid, $node->title, $ricursione, $maxricursione, $trimval, $node->book['mlid']);
   return $content;