Do this test & see what result you get
http://www3.limewire.com:6346

Do you see the firewall icon (brick wall in front of the blue globe)? Have a look through this thread about connection problems (if you havent already). Double check your port forwarding settings, maybe you missed a step? Did you set up a static IP address first?
Connection problems? Check here first!

What are your details?

OS(Win XP etc)
LW & Java version (help > about LW & you'll see)
Firewall you're using
Modem/router brand & model
ISP
Connection type (DSL etc)
Where you connect from (home, school etc)
Are you sharing a connection with other computers
Is this your first try with LW