I had been running L/W fine, and then updated Norton int sec. After that no connection. An easy way I found around this is 1st turn OFF your personal firewall. 2nd start L/W. 3rd select File and press connect, I found that connection then went straight on to maximum, after connection, turn on your personal firewall and your connection will be maintained.
I have found this to work fine, the only thing is that you need to do this each time you want to start L/W, but it only takes two ticks anyway.