diff --git a/ChangeLog b/ChangeLog
index 84e07e25c..3ae8b8e02 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-07-20  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
+
+	* SoObjects/Appointments/SOGoAppointmentFolder.m
+	(_appendCycleException:firstInstanceCalendarDateRange:fromRow:forRange:withTimeZone:toArray:):
+	return immediately if the occurrence does not have a valid
+	recurrence-id.
+
 2012-07-20  Francis Lachapelle  <flachapelle@inverse.ca>
 
 	* UI/WebServerResources/MailerUI.js (onEmailTo): append the email
diff --git a/SoObjects/Appointments/SOGoAppointmentFolder.m b/SoObjects/Appointments/SOGoAppointmentFolder.m
index 29a64b77b..50cdd92f9 100644
--- a/SoObjects/Appointments/SOGoAppointmentFolder.m
+++ b/SoObjects/Appointments/SOGoAppointmentFolder.m
@@ -863,6 +863,11 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
 
   newRecord = nil;
   recurrenceId = [component recurrenceId];
+  if (!recurrenceId)
+    {
+      [self errorWithFormat: @"ignored component with an empty EXCEPTION-ID"];
+      return;
+    }
   
   if (tz)
     {