diff -uNr moodle.orig/course/grades.php moodle/course/grades.php
--- moodle.orig/course/grades.php	2006-05-04 06:40:14.000000000 +0100
+++ moodle/course/grades.php	2006-10-05 13:32:17.000000000 +0100
@@ -113,7 +113,8 @@
                                 $columns[] = "$mod->modfullname: ".format_string($instance->name)." - $maxgrade";
     
                                 foreach ($students as $student) {
-                                    if (!empty($modgrades->grades[$student->id])) {
+                                    // paulo.matos: FIXED, consider 0 as grade!!
+                                    if ((!empty($modgrades->grades[$student->id])) || ($modgrades->grades[$student->id]=='0')) {
                                         $grades[$student->id][] = $currentstudentgrade = $modgrades->grades[$student->id];
                                         if ($mod->visible) {
                                             $gradeshtml[$student->id][] = $modgrades->grades[$student->id];
diff -uNr moodle.orig/grade/lib.php moodle/grade/lib.php
--- moodle.orig/grade/lib.php	2006-07-19 03:07:39.000000000 +0100
+++ moodle/grade/lib.php	2006-10-05 13:39:42.000000000 +0100
@@ -1268,7 +1268,8 @@
 
                                 if (!empty($students)) {
                                     foreach ($students as $student) {
-                                        if (!empty($modgrades->grades[$student->id])) {
+                                        // paulo.matos: FIXED, consider 0 as grade!!
+                                        if ((!empty($modgrades->grades[$student->id])) || ($modgrades->grades[$student->id]=='0')) {
                                             $grades[$student->id][] = $currentstudentgrade = $modgrades->grades[$student->id];
                                         } else {
                                             $grades[$student->id][] = $currentstudentgrade = "";
diff -uNr moodle.orig/mod/assignment/lib.php moodle/mod/assignment/lib.php
--- moodle.orig/mod/assignment/lib.php	2006-09-28 03:09:38.000000000 +0100
+++ moodle/mod/assignment/lib.php	2006-10-05 14:03:15.000000000 +0100
@@ -1818,7 +1818,8 @@
             if ($scale = get_record('scale', 'id', $scaleid)) {
                 $scalegrades = make_menu_from_list($scale->scale);
                 foreach ($grades as $userid => $grade) {
-                    if (empty($scalegrades[$grade])) {
+                    // paulo.matos: FIXED, consider 0 as grade!!
+                    if (empty($scalegrades[$grade]) && ($scalegrades[$grade] != '0')) {
                         $grades[$userid] = '-';
                     } else {
                         $grades[$userid] = $scalegrades[$grade];