Leave the setting at UPnP. To my knowledge Telstra doesn't block p2p unless they've just started. There's seems to be a problem with the link I gave for the test page b/c I can't reach it either lol.
OK let's try this:
1. Try deleting your LW Preferences folder whilst LW is closed; instructions here:
Fixes for Limewire
2. After opening LW you will need to reset your options, but leave everything at default except the following: Go to Tools>Options>Connections & untick connect on startup & press apply button. (Also go to Tools>Options>advanced>Startup & make sure connect on startup is unticked.)
3. Go to LW's menu File>Disconnect. Wait a minute. Then go File>Connect & wait about 10-15 mins. to see if it connects.