Gps-speedsurfing

hello i ve just posted sbn file from new session...

and i m quiete desapointed:
the resulst seen on the screen of the gt31 during this day ( several average speed during 10sec )
... and the results of the posted sbn file on this site!!!!

snb file has been uploaded from card.

it seems to be not the same result, and by far! :-)

is it normal? any ideas

thank you

ZFINS