My bet is you have a blocked port. Probably due to your wireless but let's hope if that's so ... it's not your isp.

Did you configure your firewall so it allows LW full access (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link)

Do this simple test for us. Using your browser go here: http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there?

What brand & model of connection device do you use? It would've helped had you answered the above questions. I can only help with as much as you tell us.