not showing actual traffic and conversation with Cisco 7604

im trying to cofigure netflow in my cisco 7604 router. i have already putted the following commands:

router(config)#interface gi 3/3
router(config-if)#ip route-cache flow
router(config-if)#exit
router(config)#ip flow-export destination x.x.x.x 9996
router(config)#ip flow-export source gi 3/3
router(config)#ip flow-export version 5
router(config)#ip flow-cache timeout active 1
router(config)#ip flow-cache timeout inactive 15
router(config)#snmp-server ifindex persist

now in netflow analyzer, i can see some traffic and conversations, but those figures are pretty minimum than actual. no data showing in OUTPUT...
is there any special command or configuration required for cisco 7604 router ?
please help.