As you could see from my previous post, I am using WPF Toolkit DataGrid now. One of the reason to do it is to sort data. Sure, it is possible to do sorting in ListView, but using DataGrid I can do it with less efforts.
The only problem was that what I had as data source was regular BindingList, that does not support sorting. So, sorting just didn't work.
The solution I found the easiest is using Linq. Since I assigned my data source in code, not XAML, there was no inconvenience at all.
Instead of line
ItemsSource = list
ItemsSource = from item in list select item;