Index: includes/export.inc
===================================================================
--- includes/export.inc	(revision 1144)
+++ includes/export.inc	(working copy)
@@ -468,7 +468,7 @@
   static $export_tables;
   if (is_null($export_tables)) {
     $export_tables = array();
-    $schemas = drupal_get_schema();
+    $schemas = drupal_get_schema(NULL, TRUE);
     foreach ($schemas as $table => $schema) {
       if (!isset($schema['export'])) {
         unset($schemas[$table]);