or...your 660 could freeze while near the end of the process, putting the latest mapping on your unit, but leaving the old mapping on your mac (TWICE!), even though you've checked the relevant buttons on their fucking useless Lifetime* Updater app
if i run the updater again, it tells me everything is up to date. this has left me in the position of not being able to see a way of updating just the maps on the mac to match the unit.
when it comes to software, garmin really are a useless bunch of fuck monkeys.
*the likely duration of the updating process.