I received a PDF file that no one can open. When you go to open it, Acrobat opens, but the PDF file does not. Someone that had a little background info on where the file came from said it was a security issue and that a certain plug in was need to view the file. I myself never heard of anything like this. If anyone has any info, please let me know. Thanks!
http://www.fileopen.com/
http://plugin.fileopen.com/all.php
George