If you have already setup windows xp firewall to allow needed ports you use in limewire and that doesn't help, you can try useing a different port since some internet service providers are limiting speed and or blocking some ports used by file shareing programs.

You could try useing a random port in the 50000-60000 like "50012" and make sure you setup the udp and tcp setting in windows xp firewall correctly.

If you own a router or are useing a home networking setup you may also need to setup port forwarding on that device too.

Check your internet service providers contract you recieved when you signed up, most state they have unlimited internet a month. But here is the catch read their fine print: basicaly it states the contract can be altered at any time by them and you are still bound by law to follow it.

For dsl and or other isp speed issuses or general chat check out:
dslreports.com