Have you tried opening the files from within Reader, or just by double clicking on their icons? If you can open them from within Reader, you have a file associations problem. Its solution depends on your platform.
Hi CLaudio and thanks for your speedy response.
FYI, I was able to resolve the issue by saving a PDF document on my desk top, and then going to "open with" Adobe 9.2 "these kinds of files all the time"
You wonder how these things happen out of the blue.
Thanks again, Charlie