Hi
Bit torrent and the like are peer to peer software and work on the basis that you take pieces of the item you want from people who have either the full file or part of it, in a sense this means the actual download speed is dictated by how many people are giving the file (seeding) and how fast there connection is to the internet, if for instance the majority were still on an old dial up then you would see a slow connection and download rate, however if they have a good broadband speed then the download speed would increase.
You cant do anything about the speed other than to try and get a file from those who have a good internet connection, as this isnt something you can guess at then your stuffed and have to wait for the file at whatever speed you can get it at.
I will say this, ensure your router (if you use one) has the correct ports opened on it to allow BT to connect properly, and remember that BT itself is an illegal method of sharing files and you run the risk of being taken to court for any files you choose to download.
