I used the recommendation given to me by Art Campbell on framers to set the
Tagged PDF feature to "ON" in the Acrobat Settings dialog. That solved the
problem; the book distilled to PDF without incident.
Because I have avoided using Tagged PDF (because it bloats the size of the
PDF file) in all earlier versions of FM I have used, I contacted Framemaker
Tech Support at Adobe today to see if I could have done something else to
solve my problem.
The tech support specialist told me that the failure to distill a book to
PDF is a known issue with FM 8, that it occurs regardless of whether the
book is created in Structured or Unstructured FM, and recommended that I
continue to use this work-around, or to distill each file in the book
individually, until Adobe releases a patch.
Thanks to all who took the time to respond to the original message, and
thanks especially to Art Campbell, who sent the tagging work-around, which
is the most efficient solution for me.
vallipow at gmail.com