Never have been able to find a final answer to this.  I'm using the Rieval hair prop but it's very difficult to use the morphs included with it because several of the layers have their normals reversed.  I have:

1:  Gone into the Advanced tab in the Materials editor.  "Normals forward" is already checked.

2.  Used the grouping tool to select all and then clicked "Reverse Normals".  That made the invisible ones visible and made the visible ones invisible.

3.  Followed Dr. Geep's advice and made a new group, added all to it, and reversed normals.  I got the same result as in number two above.

Anyone have any ideas about what to try next?