Index: calendar.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/calendar/includes/calendar.inc,v
retrieving revision 1.1.2.38
diff -u -r1.1.2.38 calendar.inc
--- calendar.inc	20 Mar 2009 16:21:45 -0000	1.1.2.38
+++ calendar.inc	16 Apr 2009 17:27:47 -0000
@@ -358,6 +358,12 @@
     $processed = array();
     $rrule_processed = array();
     foreach ($items as $pos => $item) {
+      // If a node does not have its two date field set, we cannot display
+      // it in the calendar, so we skip it
+      if(empty($item->calendar_fields->$fromto[0]) || empty($item->calendar_fields->$fromto[1])) {
+        continue;
+      }
+      
       $delta = !empty($field['delta_field']) && !empty($item->{$field['delta_field']}) ? $item->{$field['delta_field']} : 0;
       $real_field = $field_name;
       if (substr($field['type'], 0, 3) == 'cck') {