Problem with change of shared secret

All I am using FreeRADIUS 1.1.0 with Oracle 10. Am storing the clients data in database table 'nas' When I change the shared secret entry in this table the RADIUS server which is Already running does not seem to pick this change, and I get an error saying invalid Authenticator - however this problem does not occur if I restart the RADIUS server. Is there a way I can make the RADIUS server pick up changes to the 'nas' table dynamically? Any help would be a great help. -vishwa.