Do this test: Bug Report instructions & sample image Is the result True/False? If your result is false then you do have a firewall issue. It might be a modem/router NAT firewall.

Can you give us a total desciption of your set up:
1. OS version? (eg: Windows 98)
2. What firewalls you have?
3. Connection type? (eg: dialup, broadband, cable, etc.)
4. Modem & router brand name & model numbers?
5. Where are you trying to connect from (home, school, work, etc.)?
6. What version of Limewire (LW) & Java do you have? (Go to LW's menu Help>About LW...) Will show both LW & Java version.
7. Who is your isp provider?
8. Are you sharing the connection with other computers or p2p sharing programs? If yes, please give details of set up.
9. Is this a your 1st try at LW or is this a new problem with an experienced user.
10. 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?