In working with one of our instructors she advised that she "discovered that for the discussion assignments, if I just set the assignment to Manual posting, it will successfully hide the grades until I manually post them.  However, for a Turn-It-In assignment, both the Manual setting and the Hide setting must be activated for it to hide the grades from students."

Has anyone else experienced this?  It may be related to the thread about how content may have been imported from an older course.  But any other help would also be appreciated!