ah so you're using dial up. If you're using windows XP, then make sure you have configured it for LW; Firewall configuration instructions (click on link). Windows XP has its own firewall. Also ensure you don't have 2 software firewalls running on your computer. If you do, disable one (XP firewall for example.)

If the firewall issue is due to your internet service provider, then all you can really do is ask them to unblock it for incoming also (both TCP & UDP.) Go to LW's menu bar, Tools>Options>Advanced>Firewalls & make sure the Listening port is set to 6346. If it isn't then change it to 6346.

the company(service provider) already configured for me 6346 port and its not dial-up, for short: i have no firewall but the company has and they opened the 6346 port, which makes me pay 10$/month more than the 70$/month bill for this 56kb/s internet speed