weird problem

[Kris]

i`m using Mikrotik (Hotspot) + Freeradius + Mysql + perl postscript to 
check auth , on perl script i do check quota based on radacct table. if 
quota more than xxx Gb then you cant login.

the problem are like this what the result of accounting different with 
value that send to NAS. like this

modcall: leaving group session (returns ok) for request 1
radius_xlat:  '/usr/local/bin/rmauth.pl ADMIN 00:16:17:52:8F:94 172.1.1.248'
Exec-Program: /usr/local/bin/rmauth.pl ADMIN 00:16:17:52:8F:94 172.1.1.248
Exec-Program output: Mikrotik-Xmit-Limit = _*762**2654321*_, 
Mikrotik-Recv-Limit = _*50000000000*_, Ascend-Data-Rate=_*98304*_, 
Ascend-Xmit-Rate=_*262144*_,
Exec-Program-Wait: value-pairs: Mikrotik-Xmit-Limit = _*762**2654321*_, 
Mikrotik-Recv-Limit = _*50000000000*_, Ascend-Data-Rate=_*98304*_,, 
Ascend-Xmit-Rate=_*262144*_,
Exec-Program: returned: 0
Sending Access-Accept of id 1 to 10.128.3.3 port 1024
        Mikrotik-Xmit-Limit = _*3502655261*_ <= Above value is 
7622654321 but it send 3502655261
        Mikrotik-Recv-Limit = _*2755359744*_ <= Above value is 
5000000000 but it send 2755359744
        Ascend-Data-Rate = 98304
        Ascend-Xmit-Rate = 262144
Finished request 1


any clue bout this problem ?