The 1st problem I see is your isp but I'll discuss them in a moment. 1st, make sure your XP firewall is configured: Did you configure your firewall so it allows LW full access (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link). Recheck in any case.

Your isp is a problem. Find your ISP listed here & follow the links so you can find advice how to get around it ISP's known to BLOCK or Filter p2p or specifically Limewire. From memory, you can only use LW during certain hours of the day. If during these times you still get the brick wall, then try changing your listening port to one like 64049. ie: LW's menu bar, Tools>Options>Advanced>Firewalls.