Inaccurately reported torrent upload speed

[wow2014]

Vuze does not appear to be showing correct uplaod speeds. For instance: The reported upload speed on my torrent is 8.0kB/s, the global upload speed is about 3kB/s more, but System Monitor shows outbound traffic of 50-70kB/s, correlated to the start and stop of the torrent. I also looked at the peers list for the torrent, but it showed the same numbers as the torrent upload speed.

Once the torrent finished downloading, the reported torrent upload speed came back in line with the System Monitor numbers.

Does anyone know what might be going on?

Thanks, 
Will

Vuze 4.3.0.6
Ubuntu 14.04