--- a/includes/export.inc	Tue Nov 13 18:31:32 2012 +0100
+++ b/includes/export.inc	Tue Nov 13 18:46:22 2012 +0100
@@ -759,7 +759,7 @@
 function ctools_export_get_schema($table) {
   $cache = &ctools_static(__FUNCTION__);
   if (empty($cache[$table])) {
-    $schema = drupal_get_schema($table);
+    $schema = drupal_get_schema($table, TRUE);
 
     if (!isset($schema['export'])) {
       return array();