for example:
Open the page above, then select the item "3", It will cause that the item "2" will not able to select.
The Version of my RadControl is "2014 Q1"
<!DOCTYPE html"><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"><script type="text/javascript">function pageLoad(){ $find("DropDownList").get_items().removeAt(0);}</script></head><body><form runat="server"><Telerik:RadScriptManager runat=server /><Telerik:RadDropDownList runat=server ID=DropDownList> <Items> <Telerik:DropDownListItem Text=1 /> <Telerik:DropDownListItem Text=2 Selected /> <Telerik:DropDownListItem Text=3 /> </Items></Telerik:RadDropDownList></form></body></html>The Version of my RadControl is "2014 Q1"