[XeTeX] Inclusion of PDF graphics with XeLaTeX

[David Denton]

Hello Xetex users,

I am having problems getting XeLaTeX to consistently include
PDF's. Some work but many do not. In the latter cases, there is
simply a blank space where the graphic should be and the
following message is displayed in the log:

** WARNING ** Version of PDF file (1.5) is newer than version limit specification.
** WARNING ** No image converter available for converting file
"figs/graphic.pdf" to PDF format.
** WARNING ** >> Please check if you have 'D' option in config file.
** WARNING ** pdf: image inclusion failed for "figs/graphic.pdf".

The PDF's are sometimes generated in OpenOffice and other with
Acrobat Distiller 6.0.1. I cannot see any consistency in what
program was used to generate the PDF.

PDFlatex give me no such problems.

I am using MikTeX 2.7 and have updated my files. The XeTeX
version appears to be .999.7.

I have seen many references in mailing list archives to similar
problems, but nothing that appears to my addled brain as a clear
or definitive answer. I would very much appreciate it if someone
could offer some suggestions for this non-technical user. Must I
tell xdvipdfmx to accept v 1.5 PDFs, and, if so, how would I do
this? What is the "D option" reference about? Would installing
MikTeX 2.8 help?

Any assistance would be appreciated.

-- 
Best regards,
 David