When the DropDownStyle is set to "DropDown" on the RadDropDownList, the control will not accept a <TAB> focus. The issue appears to be caused by the hosted textbox having its TabStop set to False. Is this a bug or by design?
This workaround appears to fix the issue. Thoughts?
RadDropDownList1.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDown
oTextbox = Dropdownlist.DropDownListElement.EditableElement.TextBox.TextBoxItem.TextBoxControl