To Reproduce: Add a RadDropDownButton on a form, then create a RadMenuItem and a RadTrackBarElement element. Add the trackbar to the children`s collection of the menu item, then add the menu item to the items`s collection of the RadDropDownButton element. Application freezes when you move the drag ball and it gets close to the end of the trackbar. public partial class Form1 : Form { public Form1() { InitializeComponent(); RadTrackBarElement trackBar = new RadTrackBarElement(); //trackBar.StretchHorizontally = false; RadMenuItem menuItemTrackBar = new RadMenuItem(); menuItemTrackBar.Children.Add(trackBar); this.radDropDownButton1.Items.Add(menuItemTrackBar); } } Workaround: Set StretchHorizontally property of the trackbar to False. trackBar.StretchHorizontally = false;