If other people can test this, I think I know what's causing the other remaining lockups. There's some sort of bug with determining whether or not a line of dialog has completed. Collector, do the save files on the help page have a save right before the lockup happens or does it only have ones after? Maybe once we have all these lockups corrected you can make a new installer to patch the game to the latest version.

Oh yeah and extract this file to your C:\Sierra\Mask\ directory.