The 0/0 means this. The 1st 0 represents the number of full uploads for that file during your current session. The 2nd 0 represents partial uploads of that file during your current session.
The partial uploads come from when a host that is downloading a file has multiple hosts to upload from, and your file is one of them. The downloading host gets the piece of the file it needs from you and the other pieces from hosts that are uploading it also, thus creating what is known as the swarming effect.