PDF file received by email is blank

A company sent us a PDF attachment via email to both our internal email address and to a dial-up email account. The attachment received at our company opens using Acrobat Reader 8.0.0 but is blank. Opening the same file that was received at our dial-up email account displays properly. The PDF document is a scanned image apparently sent from a Canon iR5070 machine (the text '/Producer (Canon iR5070)' is embedded in the PDF doc code). We can open both attachments using Notepad or Wordpad and both look like valid PDF docs, but performing a file comparison shows that the bulk of the message is full of differences. I was hoping to find someone that could look at the code of both documents and determine what is wrong with the one that displays a blank page; and how to determine how it happened and thus how to correct it. It appears that the code is very similar, however the version that displays as blank is missing many accents and other symbols above each character; and some characters are different.
 
The version that works has code like this:
%âãÏÓ
ä ¯€ð>@x"Œ€ð5
 
And the version that does not display has code like this:
IO
a ????>