FreeRadius-2.2.9 - Help with NAS

Hello Everyone, I'm a newbie in FreeRadius. I have a FreeRadius 2.2.9 authentication in MySQL database, and my NAS is a Mikrotik routerboard. My dhcp-pool is MySQL. Everything is working fine, but I have a problem: I made a mistake and set different passwords on the NAS and the database. So when my client requested access the Radius Server provided an IP that was not received by NAS. The NAS then requested another one and thus my pool finish. Is there a way (perhaps post-auth) to prevent this form happening? Maybe it is checking whether the NAS received the response from the Radius Server? Thanks Aurélio