Different ssed speed (upload)

I use Bitcomet as shown in the picture.

At the begining I was seeding 4 torrents then before finishing my seeding I left one seed.
2 minutes after, my seeding speed on the upper right corner (I think it must be general upload) is still greater then the file seeding in it's line.
What can be the reason ?
Leechers ?
Or and unknown connection ?

http://turcguide.com/genel/picture.jpg