diff -Nur a/page_title.module b/page_title.module
--- a/page_title.module	2009-06-17 23:03:07.000000000 +0800
+++ b/page_title.module	2009-06-29 08:00:38.000000000 +0800
@@ -221,17 +221,17 @@
   switch ($op) {
     case 'update':
       if (user_access('set page title')) {
-        db_query('DELETE FROM {page_title} WHERE type = "node" AND id = %d', $node->nid);
+        db_query('DELETE FROM {page_title} WHERE type = \'node\' AND id = %d', $node->nid);
       }
       // fallthrough to insert intentional!
     case 'insert':
       if (isset($node->page_title) && drupal_strlen(trim($node->page_title)) > 0 && user_access('set page title')) {
-        db_query('INSERT INTO {page_title} VALUES ("node", %d, "%s")', $node->nid, $node->page_title);
+        db_query('INSERT INTO {page_title} VALUES (\'node\', %d, "%s")', $node->nid, $node->page_title);
       }
       break;
 
     case 'delete':
-      db_query('DELETE FROM {page_title} WHERE type = "node" AND id = %d', $node->nid);
+      db_query('DELETE FROM {page_title} WHERE type = \'node\' AND id = %d', $node->nid);
       break;
 
     case 'load':
@@ -347,7 +347,7 @@
  *   string the page title for the given type & id.
  */
 function page_title_load_title($id, $type) {
-  return db_result(db_query('SELECT page_title FROM {page_title} WHERE type = "%s" AND id = %d', $type, $id));
+  return db_result(db_query('SELECT page_title FROM {page_title} WHERE type = \'%s\' AND id = %d', $type, $id));
 }