Unknown Data Usage!

Hi all

One help needed.Now .I noticed that some thing is using my internet connection always.but it doesn't show up in firewall's network activity.I had similar type of problem before due to BITS service.But now even BITS is disabled.I am puzzled that BD's firewall doesn't even tell what application using my internet.I can't afford this because since my internet connection is limited in data usage.I think this not always happens but mostly.At the time of typing this thread this hadn't occur.

U can see from the image attached by me that in bytes received it is showing as 254.3 KB/S but in Out/s and In/s it shows as 0 B/s