I ain't no genius or expert just been using LW for a few yrs or more.
But I can make some suggestions:
1. 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) To disable XP's firewall: go to the control panel, double click on Windoze Firewall, check the disable box.
2. Change the compatibility mode of LW to win 2k; instructions see
Fixes for Limewire