DOCBOOK-APPS: Tex main memory exceeded when stylesheet changed.

We changed our stylesheet customization:

.............................................
(define %generate-reference-toc-on-titlepage%
  ;; #t, #f
  #f)
..............................................

from #f to #t, and now our larger publications exceed Tex's main memory:

.........................................................
Runaway definition?
->
! TeX capacity exceeded, sorry [main memory size=263001].
\g@addto@macro ...fter {#1#2}\xdef #1{\the \toks@ 
                                                  }\endgroup 
l.114260 ...endSeq{}\endNode{}\endNode{}\endSeq{}}

!  ==> Fatal error occurred, the output PDF file not finished!
..............................................................

Following Sebastian's advice for jadetex, our hugelatex file has been
working fine up to now.  It says (in part): 

................................
% hugelatex settings
main_memory.hugelatex = 1100000
................................

Any thoughts?

---
Bob