the latest firmware for the GT-31 has been released which apparently fixes some glitches with the Data Logger (I only yesterday updated mine to the now superseded V1.3B1014a). Nothing in there about fixing GPS freeze glitches though.

http://mtbest.net/setting-up-navi-GT31.htm
mtbest.net/GT31_FW_V1.3B1123T.ZIP

Cheers.

PS - Could someone who actually knows something about GPS's confirm the above information is correct.

PPS - There's some really good photos (both open ocean and pit) on Tom's website as well picasaweb.google.com/mt.best.net/Windsurfing31109SP#

chenges from 1.2 1405 > 1.3 1123:

== V1.2B1502a ========
- E.S: Trip commands added for Trip Compass Screen
- B.P.: Trip odometer calculation changed to track point based
===========================


==V1.2B1531T =======================
- Trip Compass added in [TRIP function]
- Track North up/Min Speed supported
=====================================



==V1.2B1629T =======================
- Speed genie sound/off patched (Nico)
- [MISC][DELTE][TRIP METER] will also reset stop watch (Nico)
- [MISC][[DELTE][DEL ALL] will also reset stop watch (Nico)
[TRIP METER][TRIP TIME] can be used as the time of the session with speed over [TRIP MIN SPEED]
[TRIP METER]][STOP WATCH] can be used as the time of the session
- Added [MISC][TRIP AUTO SAVE] to save trip meter data (TRP.SPD) to SD cards (Nico)
- Added "STOP WATCH","TRIP MIN SPEED"(threshold) into .SPD file (Nico)
- Added [NEW TRIP] inquiry at power on if [MISC][TRIP AUTO SAVE] enabled (Michael)
CAUTION: both trip and speed session/history data will be cleared !!!!
- [SETTINGS][INTRFACE] now supports NMEA/4800BPS (GPSPassion)

=====================================


==V1.2B1708T =======================
- 5 sec time out added for new trip inquery(Nico)
- [TRIP METER]/[STOP WATCH] revised (Paul)
- added 1/10 sec display
- displayed average speed
- removed [PAUSE/ZERO] menu to improve pause operation response time
- Stop watch is reset at power-on
===================================================================



==V1.2B1826T =======================
- Add GEOTag date time display in [SATELLITE]
- patched ESC/POWER-OFF off key lock issue
- Stop watch : 1/10 average speed display removed !
===================================================================


==V1.2B2118T =======================
- Added Instant-mark function to [SPEED]/[N AVG SPEED] - (Peter)
===================================================================



==V1.3B1012a =======================
- Added new "huge" font. Set [MISC]/[NEW FONT] on to enable the new font-(Dr.T.C.)
- Patched "DATA LOGGER" issue, improved flash memory access reliability
NOTE: The maximum size for "DATA LOGGER" function is changed to 16384.
And the max log time is around 4.5 hours.
(still under evaluation....)
===================================================================


==V1.3B1123T =======================
-Patched "Data Logger" erase issue
====================================

NotWal said...

Argh! the stupid unreadable font is my main grype about the Navi. That new font is beaut. I don't suppose there's any way to get it into a GT-11?

GT131 - all done Notwal