Hi,
Just installed on V2.2 RC2 (PHP 5 - MySQL 5).
It seems I have same problem ... I can build the product on builder_main.php but when I click on "Build Product", I go back to catalog index page and the product is not added to any category ... I wish I could get this addon working, the demo looks great ! :)
As I have many mods in my shop, I will try again to install it on a fresh new install of RC2.