You should run a test if your Vuze and BitTorrent are connectible.
In BitTorrent, it is the "Network" test in the "Setup Guide"
BitTorrent > Options > Setup Guide > check the "Network" box and run the test. The result should be a green check sign.
If it is yellow/orange or worse a red cross, something is wrong with your setup or the network between you and the other peers.
Vuze got as well an test tool, but I don't remember right know what is the path to it. ???