glibc 2.1.3-19 fixed a problem where WP Office would not load. When I
upgraded to glibc 2.1.3-21, WP Office will not load.
This errata was meant to close serious security bugs, not to fix all
the bugs in glibc 2.1.x (there are many). You should use glibc 2.1.9x
if glibc 2.1.x does not work (packages in rawhide, will appear in the next
Red Hat distribution).
ok, so the serious security bugs were also fixed in glibc-2.1.3-19?
Yes, the security bugs were fixed in -19 already.
Anyway, glibc-2.1.92 from 7.0 (or the upcomming 2.1.94 errata) should work
as well (ie. have both the security fixes and don't break WP Office).