Hello - I'm running Ubuntu Feisty on an ageing Gateway 866MHz PC, and have just installed kTorrent from Synaptic.

On the torrent I'm trying to download, I'm getting very slow speeds - 0.8kbps - and a lot of the time the message goes from downloading to stalled.

Is this likely to be due to a very low number of seeds, or should I be investigating other issues like port forwarding, throttling by ISP etc?

Thanks!

You can easily see where you should look for if you watch the peerlist. Just look at the percentage of the other peers, and whether there are any seeds yet.
This should give you a pretty good idea where to look for, port forwarding gets more important on private trackers although it is still recommended to do so anyway.