Using the program beyond compare, you can see if the files are the same. I also use it to see if wave files are the same (often not)
Also, when you create a PDF, there are backwards compatibilty issues, Make sure you set your driver for all versions back to say V8 of Adobe reader. dt To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
