I have problem to export data from ME-C3750-24TE
3750-P2-C05#sh ip flow export
Flow export v1 is enabled for main cache
Exporting flows to 80.17.42.108 (9996)
Exporting using source IP address 172.20.1.34
Version 1 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
the image is c3750me-i5-mz.122-25.EY.bin
some idea?