sort iso14651 bug

it seems sort is suffering from some subtle bug.  i am wondering, is it
just my machine, is it a redhat problem, or is it actually a gnu bug?

for example, en_IN seems to produce proper results, but en_AU fails to
handle some special characters properly.  but both of these locales use
the same stock definitions:

LC_CTYPE
copy "i18n"
END LC_CTYPE
LC_COLLATE
copy "iso14651_t1"
END LC_COLLATE

en_IN producing correct results:
$  LC_CTYPE=en_IN LC_COLLATE=en_IN sort /tmp/sos
groan
grosr
groß
grost
red
résumé
resumed

en_AU producing incorrect results:
$  LC_CTYPE=en_AU LC_COLLATE=en_AU sort /tmp/sos
groß
groan
grosr
grost
résumé
red
resumed

(glibc-common-2.3.2-27.9, coreutils-4.5.3-19)
(redhat 9+up2date)