I can provide some additional information...
After posting the article to comp.emacs.xemacs and filing the bug, I
discovered that the compilation `next-error' function also failed with
the regexp stack overflow. At this point I tried version 21.4.13, and
both oo-browser and `next-error' work. (I haven't tested oo-browser
thoroughly, but it definitely gets past the stack overflow error and
appears to work fine.) I configured 21.4.14 and 21.4.13 identically.
Also, although I mentioned it in the article I neglected to mention it
in the bug report - I had tried bumping `re_max_failures' from 20000
to 200000 and increasing the shell stack limit from 8K to 16K (with
ulimit). (These were two suggestions I came across while Googling.)
Thank you for you help.
Bill