Problem with STI tables

[saratrice]

Running rails 3.1.3. I'm using this branch:
https://github.com/stipple/acts_as_archive
and having a problem with restoring records on STI tables.

I have a User model, and a Student model that inherits from it. When I attempt to archive a user without a type, it archives and restores fine. When I attempt to archive a Student (i.e. User with type = 'Student'), it archives, but will not restore.

I know that someone had the same issue:
#22
but his fix isn't working for me. Anyone got a recommendation?