diff --git a/tryton/gui/window/view_form/model/field.py b/tryton/gui/window/view_form/model/field.py
index 371c5c7a11..93f2de0008 100644
--- a/tryton/gui/window/view_form/model/field.py
+++ b/tryton/gui/window/view_form/model/field.py
@@ -748,30 +748,38 @@ class O2MField(Field):
             else:
                 fields = {}
 
-        to_remove = []
-        for record2 in record.value[self.name]:
-            if not record2.id:
-                to_remove.append(record2)
+        group = record.value[self.name]
+        if value and value.get('delete'):
+            for record_id in value['delete']:
+                record2 = group.get(record_id)
+                if record2 is not None:
+                    group.remove(
+                        record2, remove=False, signal=False,
+                        force_remove=False)
         if value and value.get('remove'):
             for record_id in value['remove']:
-                record2 = record.value[self.name].get(record_id)
+                record2 = group.get(record_id)
                 if record2 is not None:
-                    to_remove.append(record2)
-        for record2 in to_remove:
-            record.value[self.name].remove(record2, signal=False,
-                force_remove=False)
+                    group.remove(
+                        record2, remove=True, signal=False,
+                        force_remove=False)
 
         if value and (value.get('add') or value.get('update', [])):
             record.value[self.name].add_fields(fields)
             for index, vals in value.get('add', []):
-                new_record = record.value[self.name].new(default=False)
-                record.value[self.name].add(new_record, index, signal=False)
+                new_record = None
+                id_ = vals.pop('id', None)
+                if id_ is not None:
+                    new_record = group.get(id_)
+                if not new_record:
+                    new_record = group.new(obj_id=id_, default=False)
+                group.add(new_record, index, signal=False)
                 new_record.set_on_change(vals)
 
             for vals in value.get('update', []):
                 if 'id' not in vals:
                     continue
-                record2 = record.value[self.name].get(vals['id'])
+                record2 = group.get(vals['id'])
                 if record2 is not None:
                     record2.set_on_change(vals)
 
diff --git a/tryton/gui/window/view_form/model/group.py b/tryton/gui/window/view_form/model/group.py
index 15a6423114..7602cb47a4 100644
--- a/tryton/gui/window/view_form/model/group.py
+++ b/tryton/gui/window/view_form/model/group.py
@@ -314,16 +314,17 @@ class Group(SignalEvent, list):
             record.signal_connect(self, 'record-changed', self._record_changed)
             record.signal_connect(self, 'record-modified',
                 self._record_modified)
-        if position == -1:
-            self.append(record)
-        else:
-            self.insert(position, record)
+        if record not in self:
+            if position == -1:
+                self.append(record)
+            else:
+                self.insert(position, record)
         for record_rm in self.record_removed:
             if record_rm.id == record.id:
-                self.record_removed.remove(record)
+                self.record_removed.remove(record_rm)
         for record_del in self.record_deleted:
             if record_del.id == record.id:
-                self.record_deleted.remove(record)
+                self.record_deleted.remove(record_del)
         self.current_idx = position
         record.modified_fields.setdefault('id')
         record.signal('record-modified')