How many green connection bars do you see? Do you see the firewall icon (brick wall in front of the blue globe)? Do this test with your browser & see if it works
http://www3.limewire.com:6346

First of all, make sure that you're only using 1 software firewall & that you've configured it properly for LW. Check out the link below
Firewall setup

If your modem/router has an internal firewall (they just about all do), this could be hampering your connection. If your router supports UPnP, try enabling it within the device & then choose the 'use UPnP' option in LW's tools > options > advanced > firewall config.
If that's no help, there's always manual port forwarding. Have a read through this thread & see how you go... it's got heaps of info
Connection problems? Check here first!

If you're still stuck or confused, post back with 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