We're working with merging the 20-odd papers in the journal Algebra and Number Theory
Somewhere around paper number 23, the merge breaks down: The subsection titles begin to
refer to the first page, and the table of contents page at the end (which we make separately)
doesn't link correctly back to the papers. Interestingly, the the XREF fix mentioned in
pdftk --help solves the problem. Of course, we'd rather Merge work right away.