Try deleting LW's preferences folder when LW's properly closed (if LW's still running, it won't work). If that doesn't help, delete/replace your gnutella.net file. Instructions for all are here: If LW Will Not Connect

Make sure that the Windows firewall is off, try removing all LW's rules from TM's firewall & then applying new rules. If those fixes don't help, try the other fixes in that thread.

If you're still stuck, please post back with all of your system details