Usually replacing the gnutella.net file will fix connection issues for older users, and replacing it as described here:
http://www.gnutellaforums.com/connec...t-connect.html
If you've had problems since updating LW, you may need to remove LW from the Vista firewall rules & then re-add it.
Setting up an exception for LimeWire in your software firewall (click in link)
If still no good, after 'replacing' the gnutella.net file & re-doing the LW allowance in your firewall, then try deleting your LW preferences folder whilst LW is CLOSED, yes LW must be closed. To find the LimeWire preferences folder, see
http://www.gnutellaforums.com/genera...der-vista.html
Are you using LW version 4 or 5 now? I think in PM you said you went back to 4.18 after similar problems with LW 5.
In LW 4.18, you can go to LW's menu bar, Tools -> Options -> Connections, uncheck option. Close LW. Then open, wait a few minutes until LW totally settles down. Then file menu -> Connect.