there was a mismatch between the root element and the doctype declaration;
assuming that the root element is correct, synchronizing these two changes
fixed the validation problems
The qandaset had a defaultlabel="none" attribute. This is DocBook legal, but
the XSLT layer was producing FO output that included an empty
fo:list-item-label, with the following error message:
"fo:list-item-label" is missing child elements. Required content model:
marker* (%block;)+
By omitting the defaultlabel="none", the entire problem disappears.
Also, adjusted paths for reference to the ./Annimals/ which are now in
./resources/Annimals/.
The images were supplied here as a tarball, which meant that the DocBook
processor could not read them directly out of the version control system;
adding directories for the ./images/ and the ./resources/ (which contains
Annimals subdirectory and one chap4sec26 file.
Jason Leschnik