Who is your ISP?
Such a sudden loss of connection seems to point at the ISP having started to block the ports used by P2P clients.
You could try to configurate LW or BS to a higher port, like 47058, 35248, or 64049.
In LW go Tools>Options>Advanced>Firewall and change the listening port.
In BS go Setup>Connection scroll down where you see the listening port.
But don't forget to configurate your firewall accordingly....
That might help.......
