Just did a cut and paste of the Garmin and Navi tracks. The Garmin up to 10.30 and the Navi from 10.30 to finish and the final figure is...361.41km.

I,m now happy that I can verify the distance.
What I have learnt
......NEVER edit tracks when tired
......Always save the original track FIRST
......The Navi,s internal memory isn,t big enough for distance stuff (I thought it was)
......Copy the file in the SD card not cut and paste into your file
I now have a seperate folder for my edit files so i carn,t stuff it up again...I hope[}:)]