The problem appears when converting the PDF file in a JPG file using Ghostscript.
Here is the comment given by Ghostscript :
AFPL Ghostscript 8.54 (2006-05-17)
Copyright (C) 2005 artofcode LLC, Benicia, CA. All rights reserved.
This software comes with NO WARRANTY: see the file PUBLIC for details.
**** Warning: File has a corrupted %%EOF marker, or garbage after %%EOF.
Processing pages 1 through 2.
Page 1
Loading NimbusSanL-Bold font from /usr/local/share/ghostscript/8.54/Resource/Font/n019004l.pfb... 2532456 926050 1935512 647187 3 done.
Loading NimbusSanL-Regu font from /usr/local/share/ghostscript/8.54/Resource/Font/n019003l.pfb... 2532456 953351 1955608 660219 3 done.
**** Warning: Embedded symbolic TT fonts must contain a cmap for Platform=1 Encoding=0.
Loading Dingbats font from /usr/local/share/ghostscript/8.54/Resource/Font/d050000l.pfb... 2532456 1016719 2509124 1215471 3 done.
Loading NimbusSanL-ReguItal font from /usr/local/share/ghostscript/8.54/Resource/Font/n019023l.pfb... 2532456 1046535 2509124 1220637 3 done.
Substituting .notdef for Euro in the font Helvetica
Substituting .notdef for Euro in the font Helvetica
Substituting .notdef for Euro in the font Helvetica-Bold
Page 2
**** Warning: Embedded symbolic TT fonts must contain a cmap for Platform=1 Encoding=0.
**** This file had errors that were repaired or ignored.
**** The file was produced by:
**** >>>> Virtual Print Engine PDF Server Win x86 v4.00 -
www.IdealSoftware.com <<<<
**** Please notify the author of the software that produced this
**** file that it does not conform to Adobe's published PDF
**** specification.