I have been using Joomla 2.5 for about 6 months and just trying my first e-commerce site for sales within Australia. I chose VirtueMart 2.0 and have only been using it for about 4 days. When got to setting up VirtueMart shipping I wanted way of getting the postage quotes from Australia Post. I found and purchased VM Aus Post Shipping for VirtueMart. I followed the instructions from GJC WebDesign on how to get the Australia Post API Key and install the plugin. I thought I followed the instructions but was having a lot of trouble getting any response back from AusPost. I then re-read the instructions and saw "Your units for the product need to be in centimeters and kilos!". Doh! I had mine in mm and g. After changing my product dimensions to cm and Kg the plugin started giving postage amounts. I was having problems adding the postage GST onto the total GST. I emailed the developer about the problem and after a few emails had the problem fixed. This change will help make the postage GST compliant. I was finding problems with the Australian External Territories not working properly, but that problem is really with the Australia Post API.