Bug with newest rc2

I found a bug below with nodeaccess_userreference of rc2 :
(1) It works only when grant all permission to user referred . Once less grant, an error comes out when rebuild permission

An AJAX HTTP error occurred. HTTP Result Code: 500 Debugging information follows. Path: /d7test/batch?render=overlay&id=23&op=do StatusText: Service unavailable (with message) ResponseText: PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'grant_delete' cannot be null: INSERT INTO {node_access} (nid, realm, gid, grant_view, grant_update, grant_delete) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5), (:db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9, :db_insert_placeholder_10, :db_insert_placeholder_11); Array ( [:db_insert_placeholder_0] => 18 [:db_insert_placeholder_1] => nodeaccess_userreference [:db_insert_placeholder_2] => 22 [:db_insert_placeholder_3] => 1 [:db_insert_placeholder_4] => 1 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => 18 [:db_insert_placeholder_7] => nodeaccess_userreference_author [:db_insert_placeholder_8] => 1 [:db_insert_placeholder_9] => 1 [:db_insert_placeholder_10] => 1 [:db_insert_placeholder_11] => 1 ) in node_access_write_grants() (line 3334 of /var/www/html/d7test/modules/node/node.module).