Index: mod/quiz/report/statistics/report.php
===================================================================
RCS file: /home/cvs_repositories/globalcvs/ou-moodle/mod/quiz/report/statistics/report.php,v
retrieving revision 1.9
diff -u -r1.9 report.php
--- mod/quiz/report/statistics/report.php	8 Oct 2009 16:36:33 -0000	1.9
+++ mod/quiz/report/statistics/report.php	13 Oct 2009 16:33:46 -0000
@@ -619,6 +619,12 @@
             if ($s){
                 $toinsert = (object)((array)$quizstats + $params);
                 $toinsert->timemodified = time();
+                if (is_nan($toinsert->errorratio)) {
+                    $toinsert->errorratio = NULL;
+                }
+                if (is_nan($toinsert->standarderror)) {
+                    $toinsert->standarderror = NULL;
+                }
                 $quizstats->id = insert_record('quiz_statistics', $toinsert);
                 foreach ($qstats->questions as $question){
                     $question->_stats->quizstatisticsid = $quizstats->id;