[Koha] Why we can't import bibliographic records using matching rule "LOC"?

Hi list. We use Koha 3.10.05 . We exported from Aleph all our database (260 000 records ) and imported it into Koha and it worked. But now we must export every day from Aleph and import into Koha but have this problem. We can't import bibliographic records using matching rule "LOC"? We only can import when use matching rule "Add incoming records " . Koha can't "overlay". Why? Best regars Araik В этом сообщении вирусы не обнаружены. Проверено AVG - www.avg.com Версия: 2012.0.2242 / Вирусная база данных: 3184/5865 - Дата выпуска: 28.05.2013