Programatically add UserControls that Contain an UpdatePanel

In the release notes for the latest release it states that you can programatically add UpdatePanels now. I have a user control (ascx) that contains an UpdatePanel and a Timer to refresh the panel. When I add more than one of these controls to the page programatically the first refresh of one of the UpdatePanels blanks out all of the data in all of ascx controls. When I add the controls to the page in the aspx code everything works fine. I need to add them programatically since the number of them is configurable. I have the ScriptManager control on the page with partial refresh enabled. Is there something special I need to do when I add these controls programatically?

UserControl

<%@dotnet.itags.org. Control Language="C#" AutoEventWireup="true" Codebehind="DataPart.ascx.cs" Inherits="MS.Support.KnowledgeManagement.VisualKb.DataPart"
EnableViewState="false" %>
<div class="dataPart">
<div id="divHeader" class="dataPartHeader" runat="server">
<img alt="Collapse" style='float: right' src='images/Collapse.gif' title='Collapse'
onclick="ExpandCollapse(this,this.parentElement.parentElement.children(1))" />
<asp:Label ID="lblHeader" runat="server"></asp:Label>
</div>
<div id="divBody" class="dataPartBody" runat="server">
<asp:UpdatePanel ID="divUpdate" UpdateMode="Conditional" runat="server">
<ContentTemplate>
<vkb:VkbBulletedList ID="blItems" runat="server" BulletStyle='disc' DisplayMode='HyperLink'
CssClass="dataPartList" NewIndicatorFontColor="red">
</vkb:VkbBulletedList>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="timerRefresh" />
</Triggers>
</asp:UpdatePanel>
<div style='text-align: center; width: 100%'>
<asp:HyperLink ID="lnkViewAll" runat="server" CssClass="dataPartLink">View All</asp:HyperLink>
</div>
</div>
</div>
<asp:XmlDataSource ID="xmlDataSource" runat="server" XPath="descendant::Items/Item"
EnableCaching="false" EnableViewState="False"></asp:XmlDataSource>
<asp:Timer ID="timerRefresh" OnTick="timerRefresh_Tick" runat="server">
</asp:Timer>

Code to add ascx to page

dp = Page.LoadControl("DataPart.ascx") as DataPart;
dp.DataType = "Article";
dp.HeaderColor = Color.LightGray;
dp.HeaderFontColor = Color.Black;
dp.HeaderText = nodes.Current.GetAttribute("Name", String.Empty);
dp.CategoryId = Convert.ToInt32(nodes.Current.GetAttribute("Id", String.Empty));
dp.BodyColor = Color.WhiteSmoke;
dp.EnableRefresh = false;
dp.XmlData = nodes.Current.SelectSingleNode("Items") != null ? nodes.Current.SelectSingleNode("Items").OuterXml : "<Items />";
td.Controls.Add(dp);

I tried a simple example just using a RadioButtonList against XML data source and everything seemed to work fine when adding dynamically. What's in the VkbBulletedList control?
Its just an override of the BulletedList control to add some custom text to each bulleted item.