Jukka R. explicitly stated that gpsd timestamp is not fed to the chip, so I'd say that's ruled out. But he also said "almanac and ephemeris are fed back to the chip", somthing I wasn't sure about earlier (the chip could have had an internal memory, although I guess that's unlikely). Ephemeris data has to live in /var/lib/nvd_data (That's the only file I see getting updated with the setup mentioned above). ag2, are you familiar with almanac / ephemeris data? Does the size of the file look like it's in the ballpark?