I encountered the same problem and found the solution
under the microsoft.public newsgroup. Seems as if the
error is thrown from Word, and not Outlook. To fix this
error, see:
Look for the solution under #4. Apparently, when I
installed Adobe Acrobat it created a file called
PDFMaker.dot in one of the startup paths. I renamed
(actually deleted) the file and no longer get the message
from Outlook or Word.
