Whats the go with this model
I see regularly, post from tech savvy guys and girls, of this particular model just not recording data to the cards.
The latest was from one lad from South Aus Speed Demons, who ran two at same session, and neither wrote to card
The troublesome ones cant all be duds.... can they
For those who have experienced same issue, whats the serial number on the back.
Maybe its just a batch number problem.
Oh and thank ........ I still have a workable Navi GT-11
(crossing fingers)
Not had any issues with my 31. Far less spikes. Still use the 11 from time to time when I forget the 31 (leave the 11 in the car just in case). GT31 SN 832001747.
Occasionally, you can get the GPS's to not write when you switch it on, then go sailing straight away - without letting it first "lock" onto the satellites.
You can also get it when you use an SD-card which uses the wrong voltage. The SD/MMC spec says that there are two voltages that can be used (1.8v & 3.3v), you need to make sure to use a card that supports the lower voltage... reliably (ie: some 3.3v models work at 1.8v).
no one likes to lose data 
are you locking the buttons or leaving them open?
that was the only time i have lost data on my gt11
pushed the toggle switch and paused the unit with out knowing !!
Before I started to use the Key Locker it was common to notice that the display would start flashing during the session. Now I always use the Key Locker and never get flashing display.
once again we all "do it a little bit different"
i like to see the numbers flashing, from Max speed to Max 10sec Av.
Then lock the buttons !!
I see regularly, post from tech savvy guys and girls, of this particular model just not recording data to the cards. 
