It sounds like you ran through the options suggested here
If LW Will Not Connect (click on the blue link), did you try disabling all Performance options? Whilst you deleted the gnutella.net file, did you try replacing it?
I've supplied 3 versions of my own gnutella.net files. Try each one.

Two of these are from LW 5, the other from LW 4. LW needs to be closed when you replace these.
I see your isp is optononline.
With that in mind, if all above fails, try changing listening & perhaps connection ports to something like 64049. Tools > Options > Advanced > Firewalls.