A client sent me a PDF that his author created. The author did not know how to add page numbers in his native files or in Acrobat. I added the page numbers in Acrobat, and they display and print fine from Acrobat and Adobe Reader. I'm using XI Pro.
However, the client is viewing the PDF in something other than Acrobat, and cannot see the page numbers. I e-mailed the file to myself and viewed it in Reader on the iPad, GoodReader, and on my iPhone, and I too cannot see the page numbers in this file.
To me, this is not a big deal, as the project is destined for print, and when viewed on devices, the page number issue may not be significant. But to set my client's mind at ease, I'm curious as to why this is happening. I don't think it has anything to do with the fact that the intended page size is 9 x 12, especially when I can print it at actual size and at Fit on Page without incident.