Sounds like you have inadvertently downloaded the US version of TL. This issue was fixed a long while ago and the only way you would still be experiencing it with the Aus TL would be if you were using an older version. It is one reason it is important to do updates regularly, I have mine set to update on opening. 

You may have to uninstal TL, download again making sure you do it through the Aus site and then do a full version update and import your listings from your back up file.