PDF Debugging (with the file)

Avg Bid (USD)
Project Budget (USD)
$10 - $30

Project Description:
I have a PDF which I created using PDFClown. For some reason, Acrobat reader toasts an alert "An error exists on this page...", and I don't know why.
I also don't know how to find where is the bug in the file.
To succeed you have to know the PDF structure (which I don't...)
The file is attached.

I would like to know *where* is the bug in the file, and how to fix it. (not just fix it).

Additional Project Description:
09/17/2013 at 8:20 EST
A copy of the file can be found on:

09/17/2013 at 9:13 EST
A simpler file which has the same problem can be found at the address:

Skills required:
About the employer:
Public Clarification Board
Bids are hidden by the project creator. Log in as the employer to view bids or to bid on this project.
You will not be able to bid on this project if you are not qualified in one of the job categories. To see your qualifications click here.

$ 25
in 1 days
$ 30
in 2 days
$ 25
in 3 days
Hire sijoxaviar32
$ 15
in 1 days
$ 61
in 5 days
Hire markdastreet
$ 15
in 1 days
$ 20
in 1 days
Hire Thraral
$ 19
in 0 days