No firewall tab? Ooops--I guess I forgot to ask you the most basic question: What is your OS? (Apple Menu->About this Computer). All my answers assumed you were running OSX (10.2.5) on the G3.
[edit--why don't you just delete this thread and post your question in the Limewire Mac section, as Ursula originally suggested--look around and see which forum best fits your situation.
http://www.gnutellaforums.com/forumd...p?s=&forumid=7
You can delete this thread by clicking on the edit button of your original post to see the delete option
Cheers--stief