Acct-Interim-Interval not working

[Bishal]

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?