I'm in exactly the same boat. Just updated my Imac to Snow Leopard & find 4.18.8 won't connect too. And I hate the new Limewire 5, which is why I too stuck to 4.18.8.
I tried replacing the gnutella.net file and that seems to have fixed it, thanks Lord of the Rings!
Hope you got the problem sorted douglashh?
..... EDIT: spoke too soon. That got it connected, but it seems Snow Leopard has caused more probs than just connecting.
Time to go search for answers .............