wrong interface speed

I have tested NFA , and netflowed two outbound interfaces of cisco7609 .
Some questions :
Q1,it seens it's not correct of that it shows the interface utilization is 0% . It captures the interface bandwidth in right snmp property and a community string. And the true speed is above 200Mbps of 10G .

The configuration of 7609 :
ip flow-cache timeout active 1
mls ip multicast flow-stat-timer 9
mls netflow usage notify 60 120
mls flow ip interface-full
no mls flow ipv6
ip flow-export source Loopback1
ip flow-export version 5
ip flow-export destination a.b.c.d 9996
ip flow-aggregation cache prefix

int t7/1
ip flow ingress
ip route-cache flow
mls netflow sampling

Q2, it captures just one interface (Te7/1), but when I enable "mls netflow sampling" on int t7/1 , the NFA GUI shows 5 interface , including T7/1 and some vlan-interface(SVI). The interface T7/1 shows in flow , and other show out flow. And when I disable "mls netflow sampling(just no mls netflow sampling)" , the SVI interface come to unknow state.

What can i do?