The problem with SP2 is that there's no simple one answer to solve the issues. One solution fixes it for some but not for all & likewise for other solutions posted. That's why there's been more than one solution posted. As for your firewall, perhaps you should double-check your settings. Something is blocking LW's access. Exactly what is a mystery at the moment.
Go here & what does it say?:
http://www3.limewire.com:6346/ It should say your test page was a success. If not, tell us what happened.
SP2 is totally unnecessary for the individual user. It was designed for major company's with big networks but it's even caused many of them problems. Search around the net & you'll find plenty of commentary from experts who have said SP2 is not necessary for individual users & should even be avoided.