If it's not your ISP causing the problem, it might be your modem (a lot of them have their own internal firewall).

Did you configure your firewall for LW? Instructions are in the first thread I posted yesterday Just make sure you only have one firewall running.

What's your set up?
OS is Win 98
What Java version? (help > about LW & it'll tell you)
Connection type (ADSL, dial-up etc)
Modem/router brand & model
What firewalls you're running
How long was LW working well for, before this happened
Do you share a connection with other computers

If your new modem uses UPnP, make sure it's enabled in the modem & also within LW (tools > options > advanced > firewall config > tick 'use UPnP, apply)