Hi Daffy - Sorry to not give all the info.

The SD card is 2mg and it was formatted in the GPS. It has recorded data since the new card was put in 2 months ago but has decided it cannot find the card for the last three sessions. Of course I did a pb of 51.83 2 sec peak and an alpha of 44.3 during this time

Alewi62 - The GPS unit is 4 yo and has worked without a hitch until now so I do not think my case is a warranty situation. Been wrapt with the unit.