Hello fossey,
What is happening is that in the User's Guide, the chapter numbers listed correspond to the DVDs, not the downloads. We understand the confusion with this (and we intend on creating a version of the User's Guide specifically for the downloads), but for now there is an easy solution. What you need to do is:
1) from the premix listing in the book, write down the chapter numbers that are in the premix
2) from the chapters listing in the book for each DVD, note the chapter name that corresponds to these chapter numbers
3) when creating the premix in the Workout Blender, use the chapter names, not the numbers
Hope this helps for now!