The installers on Ivory 1.7 DVDs report "Installation Failed" when the Interlok Extensions package is selected. The rest of the installation should be fine. All you need to do after running the DVD installer, is to run one of our 1.7x updaters (AU, RTAS, or VST) for Snow Leopard. These can be downloaded here: http://www.synthogy.com/downloads/mac/leopard.html