Acctstoptime same as acctstarttime

Hello, I'm using FreeRadius 2.1.12 and I gotta a database problem with the user connection registry. Can you help me? When the connection is registered, the acctstoptime field is filled with the same content from the acctstarttime field, the user doesn't loose connection but radius fills the field like it lost at the same time it started. However, when the user actually looses connection, the field gets updated to the right actual time. As of now, I can't update my FreeRadius since it's the one being used for the clients and it can't stop at any time then. Thank you in advance.