--- grade/lib.php
+++ grade/lib.php
@@ -487,7 +487,7 @@
                         // set percents and weights for each assignment
                         foreach($assignments as $assignment => $info) {
                             if ($assignment != 'stats') {
-                                if ($grades_by_student["$student"]["$category"]["$assignment"]['grade'] != $strexcluded) {    
+                                if (($grades_by_student["$student"]["$category"]["$assignment"]['grade'] != $strexcluded) || ($grades_by_student["$student"]["$category"]["$assignment"]['grade'] == 0)) {
                                     if ($grades_by_student["$student"]["$category"]["$assignment"]['maxgrade'] != 0) {
                                         $grades_by_student["$student"]["$category"]["$assignment"]['percent'] = round($grades_by_student["$student"]["$category"]["$assignment"]['grade']/$grades_by_student["$student"]["$category"]["$assignment"]['maxgrade']*100,2);
                                     }