RadGrid Issues with Filtering

this.radGridView1.FilterChanging += RadGridView1_FilterChanging;
this.radGridView1.FilterChanged += RadGridView1_FilterChanged;

string propertyName = string.Empty;
Timer t;
private void RadGridView1_FilterChanged(object sender, GridViewCollectionChangedEventArgs e)
{
    if (e.Action == Telerik.WinControls.Data.NotifyCollectionChangedAction.Remove)
    {
        this.radGridView1.SortDescriptors.Add(propertyName, ListSortDirection.Ascending);
        t = new Timer();
        t.Interval = 100;
        t.Tick += T_Tick;
        t.Start(); 
    }

}

private void T_Tick(object sender, EventArgs e)
{
    t.Stop();
    this.radGridView1.SortDescriptors.Remove(propertyName);
}

private void RadGridView1_FilterChanging(object sender, GridViewCollectionChangingEventArgs e)
{
    if (e.Action == Telerik.WinControls.Data.NotifyCollectionChangedAction.Remove)
    {
        propertyName = e.PropertyName;
    }
}