May I ask which isp?

Chances are your modem/router settings have gone back to default. See if you can enable UPnP again. Check this section 1/4 way down this page Connection problems? Check here first! (click on link)

What happens when you send your browser here? http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there?

BTW what brand & model of modem/router set up devices do you have?

Edit: Ah so you're now using ADSL instead of cable?!?! Check your LW settings also. Keep in mind you'll probably have a different ip no. so ... that may make a difference with your firewall!
Firewall configuration instructions (click on link)