diff --git a/dav_events/forms/events.py b/dav_events/forms/events.py
index 77624de..4908e92 100644
--- a/dav_events/forms/events.py
+++ b/dav_events/forms/events.py
@@ -897,6 +897,8 @@ class SummaryForm(EventCreateForm):
                                     widget=forms.Textarea(attrs={'rows': 5}))
 
     def proceed_session_data(self, session_data):
+        super(SummaryForm, self).proceed_session_data(session_data)
+
         registration_required = self._session_data.get('registration_required', False)
         if registration_required:
             deadline = self._session_data.get('deadline', None)
diff --git a/dav_events/forms/generic.py b/dav_events/forms/generic.py
index e21224f..ecf2fff 100644
--- a/dav_events/forms/generic.py
+++ b/dav_events/forms/generic.py
@@ -164,7 +164,9 @@ class ModelMixin(object):
             raise TypeError('Expected %s' % model.__class__.__name__)
         data = {}
         for field in instance._meta.get_fields():
-            data[field.name] = getattr(instance, field.name)
+            v = getattr(instance, field.name)
+            if v is not None:
+                data[field.name] = getattr(instance, field.name)
         self.is_bound = True
         self.data = data
         return data
diff --git a/dav_events/views/events.py b/dav_events/views/events.py
index 0dad282..0d942b0 100644
--- a/dav_events/views/events.py
+++ b/dav_events/views/events.py
@@ -312,9 +312,11 @@ class EventCreateView(EventPermissionMixin, generic.FormView):
                           'publication_confirmed_at', 'publication_confirmed_by',
                           'number',
                           'planned_publication_date', 'internal_note',):
-                setattr(event, field, None)
+                if hasattr(event, field):
+                    setattr(event, field, None)
             for field in ('accepted', 'publication_confirmed'):
-                setattr(event, field, False)
+                if hasattr(event, field):
+                    setattr(event, field, False)
 
             initial_form_name = self.form_class.get_initial_form_name()
             form_class = getattr(forms.events, initial_form_name)