Google pdf viewer sometimes doesn't work "Sorry, we are unable to retrieve the document for viewing ... "

i have a page where there are two links to pdf files. the first one doesn't work and show the mentioned message in the title, but the other one works fine ?? does the version of pdf file matter? as the first one is created by acrobat 9 and the other one is开发者_开发知识库 created by acrobat 7 ???

i uploaded the files to : http://en.mawaqef.net/media-center/2945

I figured out the problem, the second file is 10 megabytes in size which I think is not allowed using the Google pdf viewer.

I tried to separate the first two pages and it worked.