Your download speed depends on how many sources you're downloading from & their speed, as well as your speed. If you download from 1 modem source it's going to be slow. Also depends on how well you have your LW set up & whether your ISP shapes your bandwidth for p2p. Who is your ISP?

Do a speed test here
http://www.dslreports.com/speedtest?more=1

Download a file from here & see what speed you get
http://www.magnetmix.com/video.shtml

Heaps of info here about how to set up your LW for best performance
Configuring LW for best performance