Is this PDF defective?

Question

I have been encountering problems with the "Save as XPS/PDF..." add-in for Microsoft Office 2007. Since the update to Service Pack 3, Office has been producing PDFs that Adobe Reader/Acrobat Pro can't render correctly (before the update, there were no such problems). I have already started a thread about this at superuser.com. There the consensus was that Office does indeed produce a malformed PDF.
So far, so good - so I paid €299 plus taxes to open a support ticket at Microsoft. However, they say that since other PDF renderers like Foxit Reader or Chrome's internal PDF viewer can render the file correctly, the problem is not with Office but with Acrobat (so I guess they are trying to pass the buck to Adobe (and thereby avoid having to refund my support ticket fee which they would have to do if a bug in one of their products was the cause for it)).
My guess is that other PDF viewers are more lenient to errors in the file, just as good browsers ignore malformed HTML, but that Adobe's products (or GhostScript, for that matter, who claims that there is an error in an XREF header, whatever that is) are strict and refuse to render a defective file.
My problem now is: Can I prove that the file is in fact defective? If so, how?
You can find the PDF file here, and (if you want it) the original PowerPoint file here.
Thank you very much,
Tim Pietzcker

Answer 1

Yes the PDF is malformed. Adobe products are some of the most lenient in terms of 'bad grammar' within PDF files, but if faced with an outright error they will usually ignore that object. This can in turn cause other page elements to be hidden, e.g. where they depend on transparency information from the malformed object.
The specific error in this case is with the implementation of fill gradients on the orange shape which joins between the left pie chart and the middle pie chart. If Microsoft care, they've omitted one of the bounds values from the stitch function definition for the pattern axial fill. Deleting that shape from the PDF, everything else renders perfectly.
Obviously the best thing to do is use the Acrobat plugin to 'Save to Adobe PDF' rather than the Microsoft PDF/XPS addon (I've checked and Acrobat's plugin works fine with your PPTX file), but if you absolutely have to use the MS addon then give that shape a different style of gradient and try again.