hmm ... with a backup of the new gnutella.net file you downloaded, deleting the LW preferences & putting the gnutella.net file inside should have some effect.

Tools -> Options -> Connections. Disable option. Close LW. Open LW, wait 5+ mins. Then go to file menu choose Connect.

Another option, strangely works for connections sometimes is to remove all your Java versions & reinstall using the offline Java installer; http://www.gnutellaforums.com/333278-post2.html