AJAX AutoCompleteExtender with Scrollbar

I have the AJAX toolkit version 1.0.10301.0. I have downloaded and recompiled
with the changeset 20574 from
http://www.codeplex.com/AtlasControl...ngeSetId=20574 which says it has fixed this exact problem.

I still get the same behaviour. When I click on the scrollbar it collapses
and loses focus of the textbox my code is as follows

<asp:TextBox runat="server" ID="txtBarcodeProduct" Width="400px"
CssClass="barcodeInput" TabIndex="5"></asp:TextBox>

<div id="listPlacement" style="height:100px; overflow-y:scroll;" ></div>

<cc1:AutoCompleteExtender
runat="server"
ID="autoComplete1"
TargetControlID="txtBarcodeProduct"
ServicePath="~/webservices/AutoCompleteNew.asmx"
ServiceMethod="GetCompletionList"
MinimumPrefixLength="1"
CompletionInterval="1000"
EnableCaching="true"
CompletionSetCount="12"
CompletionListElementID="listPlacement"
></cc1:AutoCompleteExtender>

I don't know what else to try, any suggestions would be greatly appreciated.

TIA
Rachel