No Netflow data from 6509

I am on day 15 of my eval of NFA 4. I have enabled netflow data on our 6509 (native) but have noticed that "ip flow export" shows that no netflow data is passing to the NFA.

Result of "show ip flow export" command:
Flow export v5 is enabled for main cache
Exporting flows to 172.16.100.41 (9996)
Exporting using source interface Vlan310
Version 5 flow records
0 flows exported in 0 udp datagrams
0 flows failed due to lack of export packet
0 export packets were sent up to process level
0 export packets were dropped due to no fib
0 export packets were dropped due to adjacency issues
0 export packets were dropped due to fragmentation failures
0 export packets were dropped due to encapsulation fixup failures
0 export packets were dropped enqueuing for the RP
0 export packets were dropped due to IPC rate limiting

I've followed the NFA instruction manual closely. Is something preventing netflow data from being passed? Is there something else I can check on the switch?

I know NFA is working because I am receiving netflow data from my Cisco 3845 T3 router and it is fine.

Thanks for your help!