Please be sure that you are hitting the back button on your browser at the end of each chapter to use the link in the "Files" section to access the next one. I just now cycled through all six chapters and they opened flawlessly for me.
If you have problems when using the links in the "Files" section (and NOT the hyperlink at the bottom of the chapter), sometimes re-trying a couple of times will result in success. Occasionally, Yahoo has problems like this, but they are not constant.
If you continue to have trouble, please let me know!
~~Wiccan~~