Just out of curiosity, if you have a GPS-NAV, please take a look at
one of your IGC files and check the HFRHWHARDWAREVERSION field
(only). I'm aware of units that put 38, 39, and 2.39 in this field.
If you find another number, please email the IGC (and CAI file if you
have it) file to marc.ramsey at gmail dot com...

Thanks,
Marc