Yes, we have dozens of "no connection" problems.
Let me describe my setup:
Vista Home Premium - SP1
ISP: Comcast Internet Cable (ave. down= 16170kbps, up= 1020kbps)
Softw Firewall = Comodo Pro
Router Wireless = Linksys WRT54G
Softw AntiVirus = BitDefender 2009
I do not use MS Firewall or Defender.

Limewire (worked without a problem until updated with 5.0.11 Java 1.6.0.11) Free Version

Problem = it displays Connecting for over 1 minute then "No Internet Connection". Mind you, I am capable of using the Browser and access Internet sites while Limewire saids No Internet Connection.

Limewire Options: Unsafe Categories (both unchecked).
Advanced Tools - Port 6346

Other than using a newer version of Limewire, everything else tell me the firewalls are not at fault.

Please help.

Test performed =
Disabled Software Firewall (failed to connect as before)
Disabled Router Firewall (failed to connect as before)
Rebooted and repeated (failed to connect as before)