Has anyone (who can get their gps to work more easily than me) captured the NMEA sentences for the Almanac data? If so, could they post them and nvd_data for people to take a look at please?

The ephemeris data aren't exported in the NMEA output afaik, so we'll have to work out the format ourselves. The other problem is that the GPS chip may need to be told to output and intput the almanac/ephemeris data (perhaps why there are lots of 0x0s in nvd_data).