Index: plugins/itip-formatter/itip-formatter.c
===================================================================
--- plugins/itip-formatter/itip-formatter.c.orig
+++ plugins/itip-formatter/itip-formatter.c
@@ -1860,6 +1860,26 @@ idle_open_cb (gpointer data)
 	return FALSE;
 }
 
+static gboolean
+is_gw_item (icalcomponent *icalcomp)
+{
+	icalproperty *prop;
+
+	prop = icalcomponent_get_first_property (icalcomp, ICAL_X_PROPERTY);
+	while (prop) {
+		const char *x_name, *x_val;
+
+		x_name = icalproperty_get_x_name (prop);
+		x_val = icalproperty_get_x (prop);
+		if (!strcmp (x_name, "X-GWRECORDID")) {
+			return TRUE;
+		}
+
+		prop = icalcomponent_get_next_property (icalcomp, ICAL_X_PROPERTY);
+	}
+	return FALSE;
+}
+
 static void
 view_response_cb (GtkWidget *widget, ItipViewResponse response, gpointer data)
 {
@@ -1906,7 +1926,7 @@ view_response_cb (GtkWidget *widget, Iti
 			if (status) {
 				e_cal_component_rescan (pitip->comp);
 				flag = update_item (pitip, response);
-				if (save_schedules && flag)
+				if (save_schedules && flag && is_gw_item (pitip->ical_comp))
 					delete_invitation_from_cache = TRUE;
 			}
 			break;
@@ -1916,7 +1936,7 @@ view_response_cb (GtkWidget *widget, Iti
 			if (status) {
 				e_cal_component_rescan (pitip->comp);
 				flag = update_item (pitip, response);
-				if (save_schedules && flag)
+				if (save_schedules && flag && is_gw_item (pitip->ical_comp))
 					delete_invitation_from_cache = TRUE;
 
 			}
@@ -1935,7 +1955,7 @@ view_response_cb (GtkWidget *widget, Iti
 			if (status) {
 				e_cal_component_rescan (pitip->comp);
 				flag = update_item (pitip, response);
-				if (save_schedules && flag)
+				if (save_schedules && flag && is_gw_item (pitip->ical_comp))
 					delete_invitation_from_cache = TRUE;
 			}
 			break;