Test and Quizzes malfunction when prof uses ADJ to enter grade for student.

A student didn't take the quiz,
The professor was trying to submit a 0 for the student and have that go to Gradebook.
The ADJ field in T&Q UI doesn't allow a 0 initially but the work around is to enter another number first, then once that's posted to Gradebook, submit the 0 score.
The Professor entered a score > 0 in Test and Quizzes using the ADJ field in the UI.
This score went to Gradebook as it should have.
Then the prof entered a 0 using the ADJ field again.
This time though the work around didn't work. The score > 0 didn't change.
Our program manager thinks the problem has something to do with programming handling of the ForGrade bit.

Ideally, the ADJ field should work like an override opportunity for a prof to submit a 0 for unsubmitted grades.