arps77 are you using Win XP SP2? If so, keep in mind what this update does. It changes your firewall settings back to default & reduces your port availability (to my understanding.) Have you applied the patch for sp2 yet? There's the recent official MS patch & there was an earlier 3rd party one (both have solved 'some' people's probs but not everybody.) Search the forum for sp2 or service pack for more suggestions about how some people solved this issue for themselves. There's also this: SP2 & Limewire: relax, it works

Firewalls is not my area, but I'm a little curious why you chose port 2456?! Also see this: Firewall & Port Setting - Some Useful Links & also alternate ports: Alternative Connection Ports - Information