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)