Invalid Arguement in AutoComplete Extender

Hi,

I was playing with the autoextender complete functionality and when i start using the backspace the list width starts shriking...if this is done for couple of times.(around 10 times) in my case this list becomes a thin line and then autocomplete exenteder throws "Invalid Arguement Error"

Can someone tell me how to fix this error.

Regards,
Vishwanath

I testedasp:AutoCompleteExtender?with?Ajax?Futures?Dec?CTPin?my?PC?and?found it?worked?fine.
Here?are?some?sample?codes?for?your?reference.
<div>
<asp:UpdatePanel ID="upnlCallWebService" runat="server">
<ContentTemplate>
<asp:TextBox runat="server" ID="txtClientName" MaxLength="50" Columns="50"></asp:TextBox>
<asp:AutoCompleteExtender ID="AutoCompleteExtenderClent" ServicePath="~/Web Services/WebService.asmx"
ServiceMethod="HelloWorld" MinimumPrefixLength="1" TargetControlID="txtClientName" runat="server">
</asp:AutoCompleteExtender>
<asp:Button ID="btnCallWebService" runat="server" Text="Call WebService" OnClick="btnCallWebService_Click" />
<asp:Label ID="lblWebService" runat="server" Text="Web Service"></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnCallWebService" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
</div>
Can you post some codes here if you have the exception message"Invalid Arguement Error" ?
Wish the sample codes can help you.