In limewire go to tools>Options>Uploads>Basic, and check and see what the upload bandwidth is set at.
If thats not it check to see if you have a firewall interfering with LW. Look for the globe icon at the bottom of LW. Is there a brickwall in front of it?
If your not firewalled, then i would tend to think that your ISP is limiting your upload speed for P2P apps.
This thread might help:
http://www.gnutellaforums.com/showth...threadid=51357