It appears that the embedded font in the pdf file is corrupt. You can try to create the pdf file. I frequently create pdf files using Apple technology when the end result is not important. For anything that requires quality output I use Acrobat to create pdfs. The results are more reliable.
Thanks for the reply.
I think I have narrowed this down. It seems to happen whenever I apply any effects to the fonts
i.e old style figures or shading - these are all in the font menu within Aperture. If I remove these and
use the basic font it reads OK.
As all the pdfs I have produced read perfectly in Apple's Preview I am left wondering if I should just delete
Reader and use Preview. Problem with this is if there actually is something wrong with the pdf and I want to send
it to be printed.
By the way the pdfs are also produced within Aperture as part of the buy book process. When I looked
at the file info it said they were produced by Mac osx quartz. i am not sure if its possible to make your own
pdf and send to Apple to be printed as a book.
thanks for this -I am going to downgrade right away!