Just for the record, my problem wasn't with case sensitivity.  Turns out
the Editor= owner@site,(list) was specifying the wrong (list).  We had
just 'cloned' a list and created a new list of approved editors, but
didn't change to the new editor (list) in the new header, was still
pointing to the old one.  The issue was with a new editor added to the
new list :-(

Jeff