web page error with script manager

[Dkv]

I added a progress bar on my page as shown in the code. But this page started giving me this error:Line: 1429
Error: Sys.ArgumentTypeException: Object of type 'Object' cannot be converted to type 'Array'.
Parameter name: array

This error is associated with script manager. Which ever page I put the script manager, it starts giving me the same error. Please help me to remove this error.
asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">

02	<asp:ScriptManager ID="ScriptManager1" runat="server">    </asp:ScriptManager>

03

04

.....

05

06

.....

07

08	<asp:UpdatePanel ID="UpdatePanel1" runat="server">

09	<ContentTemplate>

10	<asp:UpdateProgress runat="server" ID="UpdateProgress1" DynamicLayout="false" AssociatedUpdatePanelID="UpdatePanel1">

11	<ProgressTemplate>

12	<img id="Img1" runat="Server" src="~/images/cartoon.gif" height="50"  alt=""/>

13	</ProgressTemplate>

14	</asp:UpdateProgress>

15	<asp:ImageButton ID="btn_save_preferences" runat="server" Text="Save Preferences" ImageUrl="images/btn_original_savepreferences.png" onclick="save_preferences"  />

16	</ContentTemplate>

17	</asp:UpdatePanel>

18

19

...

20

21

...

22

23

24	</asp:Content>

[Prangadj]

Not sure how this concerns Telerik - post questions for ScriptManagar and UpdatePanels in the asp.net Microsoft forums.

Prangadj