Mac OS Mavricks text / script in document corrupted

Hey guys ive got a problem with a customers Mac laptop he has just upgraded to the new OS i believe its called Mavricks or something, He is writing a book and its getting published soon.

He inserted a small image into one of the pages of the 254 page document and its corrupted alllll of the text into some weird looking script. Its also a pdf document if that means anything, I dont do alot of work on Mac's either

If anyone could help me out thatd be great im thinking maybe theres a patch to fix it, if! it was the OS upgrade that caused the problem or maybe a text / script translator? Ive also attached a picture of one of the pages.

Regards, Luke.