If that post by farq11 that you have quoted is a correct assessment, Garmin would be well on the way to getting sued by any recent and current buyers of the downloadable AU lifetime maps,
Interesing too that after updating thru Garmin, the "NEW" sensis map won't appear in Mapsource until the "old" version is removed. Previously all map update versions showed in Mapsource. Now the sequence is broken. Maybe Mapsource sees the new update map (2013.20) and the earlier version (2013.10) as the "SAME" map too.