Hey guys -
Thanks for the addn'l info that voice nav was working on YOUR phones. Sort of eliminated the google app and the google servers as the source. I did yet another reboot, only this time, with a battery pull. Strangely enough, that fixed the problem!
Man, these droid phones are weird. Problems turn up for no apparent reason, but at least I finally got this one resolved. If pacemakers had the same reliability as these phones, there would be an awful lot of dead guys lying around out there.