Could be your ISP using traffic shaping on P2P

If you could tell us a bit more about the setup. Like e.g. your ISP maybe some site would mention if it's not P2P friendly. Seriously try and anwswer all the questions not just some.

You could be picking bad downloads as well

Try some of the tips in here and see if you get better speed

How to find music

There is a lot of spam on the Network and these are ways to get around it