lol how many do you have connected to your system? Give us the brand name & model of each device that's connected between your computer & the net.
For your Firewall(s) you'll need to allow LW access thru it so for instructions go to: http://www.limewire.com/english/content/firewalls.shtml & you'll see a link for Norton at the bottom of the page. Windows XP you'll also need to set it up as the guidelines suggest in order to allow both Java & Limewire (LW) access.