Hello Watermen,
You can read a full thread on this issue here:
http://www.japanesepod101.com/forum/vie ... php?t=3602
But to summarize: the new PDF system uses Adobe's CID-0 non-embedded font structure. This allows us to produce the PDFs with improved usability and features, however, not all PDF readers properly support Adobe's standard 100%. If you are using Preview, then it will not show the Japanese characters correctly, as you have already discovered.
You can try a different PDF reader, such as Adobe Reader. Or, you may download the "Lesson Notes Lite" PDF from the site. The "Lesson Notes Lite" PDF is very similar to the older PDFs and will work in Preview.
Sorry for the inconvenience, and great to see you back on the site
Charles