It appears something triggered a permanent change to gpsd from /dev/pgps in both Maemo Mapper and Mapper. Even when settings point to /dev/pgps, Maemo Mapper is trying to access gpsd, and eventually pops up an error when gpsd is not running.
I followed suggestions in George's document on clearing the cache, but it didn't make any difference. Maybe somebody can list all configuration files that Maemo Mapper is using, so we can try fixing it manually?