Update Panel Displaying Characters on Page

I have the following control inside an updatepanel:

<asp:UpdatePanel runat="server" ID="update"><ContentTemplate><telerik:RadMenu ID="handsetMenu" runat="server" OnItemClick="handsetMenu_ItemClick">   <Items></Items>                                           </telerik:RadMenu>  </ContentTemplate>                    </asp:UpdatePanel>

For some reason when it loads on the page it loads the text 2055|updatePanel|ctl00_MainContent_ctl00_MainContent_handsetMenuPanel| next to the control??  The update panel is working fine and doing what it should, but why is this text loading on the page? Any ideas?