Acct-Interim-Interval not working

Hello all, I am using freeradius 2.1.6 on FreeBSD 7.2 and using rp-pppoe server 3.10 on gentoo linux. During live session it is not updating acct-input/ouput-octets. Earlier with mpd pppoe server on freebsd it was working fine accounting input and output octets were updating every 5mins as configured in mpd server but now I have migrated my pppoe server to rp-pppoe and it's not updating account values. I have set in radgroupreply table as: 34 | Unlimited Premium | Acct-Interim-Interval | := | 300 | 35 | Unlimited Premium | Acct-Status-Type | := | Interim-Update I want to create mrtg graph of users online but due to this problem I am not able to. Any help?