thanks for all these references! After posting my last reply, I booted the
live Trisquel image, and mounted my /home partition. When I changed to my
home folder, I was never prompted for passphrases, and I could read all the
files. This suggests a bug in ubiquity, with the effect that, choosing the
manual partition negates the action of checking the "encrypt my home folder"
setting. It looks like I'll have to create another root user, and do this
encryption manually; I found this reference for the procedure.
http://ubuntuguide.net/how-to-encrypt-home-folder-in-ubuntu-12-04
thanks, all,
Dave