So I have a zl card that I made a map on. The original map was done with auto chart pro and 1199. Then I upgraded to Onix and I was able to put the card in and re scan some areas and it would just rework that portion of the same map. I tried this on my Helix 10 mega and my old map went completely away and just the new data from the Helix 10 is on there. Did this rewrite my whole map or am I missing a setting somewhere?