best example: LPRng: can't load lpr, checkpc, lpd because ld.so cannot
resolve "stat".

suspect ld.so; tried  manually loading libc.so.6 from glibc-2.2-9 and
problem persisted.
can't coerce it to use any but installed ld.so.

how do you safely back down from 2.2-12? glibc-2.2-12.i386.rpm was split,
with a new file glibc-common-2.2-12.i386.rpm. downgrading, there's nothing
to erase the glibc-common package. you probably don't want to just erase
glibc-common before the downgrade... or do you?