We have a desktop that is at least 6 years old. My husband was getting that message every time he opened a PDF file from his e-mail account and tried to print it. We saved the PDF file to Documents and when we opened it and printed from it, it worked just fine. I know that we can’t expect this computer to last much longer, but I’m surprised it’s lasted this long being as it went through Hurricane Katrina.
You may have a version of Reader that was loaded over an old one. I had a similar problem with Acrobat (the editing version).....you pretty much have to completely remove the old version then install the new one pristinely. It also messed up the opening of my Excel files directly when double clicking a file...