What happens when you try to download? Do files move into the download pane? If they don't, click on the link below & try that advice.
License (click)

Or, do files sit connecting for ages & then get stuck needing sources, but never download? If that's the case, you're probably seeing fake files. check out the links below for advice & tips.
Fake files showing up in search results
How to find music (tips for movies as well)

Don't use Windows & Norton firewalls together, they'll conflict with each other Disable the Windows firewall & configure the Norton to allow LW.
PortForward.com - Free Help Setting up Your Router or Firewall
http://www.gnutellaforums.com/226610-post6.html

What's the brand & model of your router? Most routers have an internal firewall.
Is your LW properly connected (how many green bars do you see)?