Map OK in Alpha 100 but says corrupt in Drivetrack 71, why?
Have several Alpha 100's all with same unlocked map cards, all good but none of those cards work in a new Drivetrach 71, why?
All help appreciated.

BTW, purchased a new Garmin Topo Australia & NZ V6 map and it's useless in the forest. The rivers and tracks are not named and the contour lines are so heavy and close together that all other detail (and not much of that anyway) is "smothered". Phoned Garmin help line and emailed then screenshots and 90 minutes of them helping me try all settings made no improvement.
The underlying issue is that the Garmin web page selling the Topo V6 map (for $199) has a screenshot of a place near to me, a town called Walhalla, the detail in that advertised screenshot is good and what I want so I purchased but as said the map is useless and has nowhere near the advertised detail, I supplied the "Walhalla" screenshots to the Garmin people and compared that to their advertisement to show them that the supplied map was nowhere near as good as the advertised map and they said "they would get back to me".......still waiting.