diff -Naur original/simple_access.module modified/simple_access.module
--- original/simple_access.module	2011-06-24 10:14:00.000000000 +0200
+++ modified/simple_access.module	2011-06-24 10:15:01.000000000 +0200
@@ -260,7 +260,7 @@
 function simple_access_node_delete($node) {
   foreach (array('simple_access_node', 'simple_access_owner', 'simple_access_profiles_node') as $table) {
     db_delete($table)
-      ->condition('pid', $pid)
+      ->condition('nid', $node->nid)
       ->execute();
   }
 }