Poor download speed, 0-3 kb/s

[Finagin]

Limewire downloaders
I just downloaded Limewire pro and installed it on a Windows Vista machine with a cable connection to the network from home. I dissallowed the firewall for Limewire. Other applications ie. web browsers and email work fine. My problem is that when I select music or video for download, I get very slow download speeds from 0-3 kb/s, that take forever to download. And when I select "connect" to do searches it takes a long time to connect and when it does I usually get a poor to fair connection, occasionally it gets a good and turbo connection. Does anyone know what I need to do to get a faster download speed connection? When I first installed Limewire 2 months ago I initially got really fast download speeds around 15-20 kb/s, and it has steadily dropped down to 1-3 kb/s. sometimes it will sit with 3-4 downloads at 0 kb/s. Very frustrating. I thought by paying for the Limewire Pro, I would be able to get faster dowload speeds. Please help!!!
I just checked my internet download speed and it says I have 502 kbps, so I wonder why I can only download through Limewire at 0-3 kbps.
Thanks
Finagin