netflow config on a 12000

Hello I have a GSR here and am evaluating netflow analyzer 4 for purchase in future, I did install it and configure the router and can see results, I have a problem though that the results are not matching my MRTG readings, actually they seem not realisitic !

am polling for example a gigabit interface that is about 45% utilized, though I see max utilzation of 3 Mbps on the analyzer, I also can't see some customized reports outputs for certain network ranges as source,

I would like to note that I have enabled netflow sampled on the interface and that the IOS version is 12.0(26)S1, below are the router configurations set

ip flow-cache timeout active 1
ip route-cache flow sampled input
ip route-cache flow sampled output
ip flow-export source GigabitEthernetx/x
ip flow-export version 5
ip flow-export destination x.x.x.x 9996
ip flow-sampling-mode packet-interval 100

Thanking you in advance