diff --git a/SoObjects/Appointments/SOGoCalendarComponent.m b/SoObjects/Appointments/SOGoCalendarComponent.m
index d2a98d867..762139774 100644
--- a/SoObjects/Appointments/SOGoCalendarComponent.m
+++ b/SoObjects/Appointments/SOGoCalendarComponent.m
@@ -140,6 +140,14 @@
   return aclManager;
 }
 
+- (NSException *) changeParticipationStatus: (NSString *) newPartStat
+                               withDelegate: (iCalPerson *) delegate
+                                      alarm: (iCalAlarm *) alarm
+{
+  // Required for protocol <SOGoComponentOccurence>
+  return nil;
+}
+
 - (id) init
 {
   if ((self = [super init]))
diff --git a/SoObjects/SOGo/SOGoParentFolder.m b/SoObjects/SOGo/SOGoParentFolder.m
index 501f90f9f..eb454dc97 100644
--- a/SoObjects/SOGo/SOGoParentFolder.m
+++ b/SoObjects/SOGo/SOGoParentFolder.m
@@ -433,7 +433,7 @@ static SoSecurityManager *sm = nil;
       error = [self appendPersonalSources];
       if (!error)
         if ([self respondsToSelector:@selector(appendCollectedSources)])
-          error = [self appendCollectedSources];
+          error = [self performSelector:@selector(appendCollectedSources)];
       if (!error)
         error = [self appendSystemSources]; // TODO : Not really a testcase, see function
       if (error)