Boost Theme: Stepped through each of the changes and worked perfectly. 

Clean theme: Stepped through each of the required changes to grading method and worked for Highest Grade, First Grade, Last Grade. Is supposed to calculate  the "mean" of the scores but does not, does not do much of anything, sits and cogitates, contemplating nothing, not hanging, just does nothing. 

Tried several different combinations of students and grades by resetting the course, but no improvement.