Programmatically jump to next/prev row between groups

[Paweł]

Hello!
I'm designing RadGridView and I've got case.
First of all - here is my code:

var cmd = default(RoutedUICommand);
switch (newVal)
{
    case Go.Previous:
        {
            cmd = RadGridViewCommands.MoveUp as RoutedUICommand;
        }
        break;
    case Go.Next:
        {
            cmd = RadGridViewCommands.MoveDown as RoutedUICommand;
        }
        break;
}
if (cmd != null && cmd.CanExecute(null, gridView))
{
    cmd.Execute(null, gridView);
    var selectCmd = RadGridViewCommands.SelectCurrentUnit as RoutedUICommand;
    if (selectCmd != null && selectCmd.CanExecute(null, gridView))
    {
        selectCmd.Execute(null, gridView);
    }
}

When I'm going next element to end of group and try to pass to the next group next group is opening, but first element of second group is not selected (!). When I hit "next" button second time - second item of second group selects just passing first.
How can I manage it? I tough about event handler to select first element of just opened group, but GroupRowIsExpandedChanging is not working.
Kind regards!