I was having this same problem. Tried so much to fix it...and it finally works!!!

In control panel > windows firewall >

general > leave it ON

exceptions > limewire (checked, and i didn't add it)
exceptions > limewire swarmed installer (unchecked, and i didn't add it)
i did not add a port to listen on. i tried this at one point...but it did NOT work

advanced > 1394 connection (checked) settings... UPnP TCP (checked!) UPnp UDP (checked!)
advanced > local area connection (checked) settings... UPnP TCP (checked!) UPnp UDP (checked!)
advanced > wireless ntwk connection (checked) settings... UPnP TCP (checked!) UPnp UDP (checked!)