Make sure Vista's firewall is disabled.

http://www.gnutellaforums.com/genera...on-worked.html

http://www.gnutellaforums.com/genera...onnection.html

Make sure both account LW's are not attempting to connect using the same port. Your router will reserve particular ports for each account & block the other account for listening from those same ports.

If LW 4 Will Not Connect (click on the blue link)

BT Home Hub Explored & make sure the firmware is up to date: BT Home Hub Unofficial F.A.Q (probably need to reboot router after update)
Then see if LW's connection improves. If not see below: (port forwarding for one user)

BT Home Hub Unofficial F.A.Q for both TCP & UDP same port range or one rule for each. Alternate instructions here under BT: PortForward.com - Free Help Setting up Your Router or Firewall