Thank you
I am aware that for viewing PDF files Acrobat works for both Windows and Mac OS based computers. But the software that Apple includes on their computers is not capable of handling certain types of PDF files (not at the moment at least). To make it easier for the mac community that doesn't use Acrobat for various reasons Jpod staff kindly supplies the Lite version of each PDF file, like for example the most recent "Video #32 - Video Vocab Lesson # 10" has both regular Lesson Notes (viewable with Acrobat only) and Lesson Notes Lite (Acrobat not needed).
Now, why am I explaining all this stuff? Because the older files that your iPod can open are like those Lesson Notes Lite while the new files are the new regular Notes that offer more, but are also more complex... and since Apple is also manufacturing iPods, the same software is (or isn't in case of Acrobat Reader) included, which would then explain why you are not able to view the new PDF files.
Which brings me to the next question.... have you tried opening the Lesson Notes Lite on your iPod? I am really just being curious about iPod Touch limitations... and I really want that thing