Projection's now sorted, but unfortunately, MapPoint does not use what it says is 9200m where the projections swap.

Using the mappoint altitude slider:

In the data-populated map areas, whilst increasing altitude, the map will change from Orthographic to Miller at 11000m. Whilst decreasing altitude, the map will change back to Orthographic at 8000m.

In non-data-populated map areas (E.g., Australia), whilst increasing altitude, the map will change from Orthographic to Miller at the same 11000m, but whilst decreasing altitude, the map will change back to Orthographic at 6000m!

This makes it pretty hard to predict where to use each projection. Any ideas?

Cheers,

Dave