Some ISPs throttle bandwidth for p2p applications...p2p use accounts for a lot of internet traffic. If your ISP is limiting the amount of bandwidth available then you'll see slow down/upload speeds.

Try connecting outside of peak hours. You can also try changing ports within LW. Tools > options > advnced > firewall config. change LW's listening port to something between 49152 and 65535 (like 64049 or 65000) > apply > ok.
This may not help, but it's worth a try

If you do change ports, remember to also change the port forwarded within your router setup.