I found that GridView does not work correctly with paging and QueryableCollectionView.
I have a GridView and pager:
ObservableCollection<User> m_collUsers = new ObservableCollection<User>();
//PagedCollectionView qcv = new PagedCollectionView(m_collUsers);
QueryableCollectionView qcv = new QueryableCollectionView(m_collUsers);
gvUsers.ItemsSource = qcv;
pagerUsers.Source = qcv;
now if I add or remove objects to m_collUsers GridView is not updated. Without paging or with PagedCollectionView works ok.