online users and LNS users are not equal and fluctuating

Dear Sir, I have FreeRADIUS Version 2.2.0, I have 3 Clients (3 LNS Cisco routers) and I am facing problem that online users are not stable in radius. Details: LNS01(Cisco), LNS02(Cisco): handle same users found in freeradiusdb. BUT in radius, LNS03 is not handling same number of users found in LNS03(Cisco). they are fluctuating all time. configuration of cisco LNSs are same. and I don't know from where the problem comes from. note: on LNS03(cisco) the users are stable but the problem in radius online users. please help.