Unaccounted traffic ( above 50% of total traffic) in "yesterday report"

Unaccounted traffic ( above 50% of total traffic) in "yesterday report"

Hi!
 
We have problem with version 7.7 (enterprise edition).
When I see report traffic for yesterday, there's about 70 percent of all traffic displayed as "unaccounted traffic".
 
I enclose file which shows this situation.
 "Recourd count"  is set to 100  (in Admin Operations/Settings/Netflow Settings)
 
At this moment statistics presented by Netflow are not very useful for us.
I'm looking forward to hearing from you and your help in this issue.
 
 
Regards
Tom