Commented Issue: Problem With IE8 and TabPanel [23482]

I have an app the works fine with IE7. When using EI8 I get the intermittent error: Sys.InvalidOperationException: Component 'ctl00_PageContent_tcTabs' was not found. The first time I access a page with a TabPanel on it, it usually works. When I either re-access the same page or access another page with a TabPabel on it, I get the error. The TabPanel is enclosed within an UpdatePanel. The ScriptManager is located within the master page.

I am using Visual Studio 2008. The toolkit version is 3.0.30512.1 The problem does not occur when I run the app within Visual Studio, nor when I run the app on localhost. It only fails on the remote production server.

The first function in the failing call stack is:
Sys.Application.add_init(function() {
$create(AjaxControlToolkit.TabPanel, {"headerTab":$get("__tab_ctl00_PageContent_tcTabs_tpGeneralFields"),"ownerID":"ctl00_PageContent_tcTabs"}, null, {"owner":"ctl00_PageContent_tcTabs"}, $get("ctl00_PageContent_tcTabs_tpGeneralFields"));
});

This appears to be some sort of timing problem.

Here is the contents of the UpdatePanel:
<asp:UpdatePanel ID="upMain" runat="server">
<ContentTemplate>
<ajaxtk:TabContainer runat="server" ID="tcTabs" Height="200" ActiveTabIndex="0" Width="720" AutoPostBack="false" >
<ajaxtk:TabPanel runat="server" ID="tpGeneralFields" HeaderText="&lt;span class='tabPanelSmall' title='General Fields'&gt;General Fields&lt;/span&gt;" ToolTip="General Fields" >
<ContentTemplate>
<table border="0" width="720" cellspacing="0" cellpadding="0">
<tr>
<th align="left">
Type Of Service:
</th>
<td>
<asp:DropDownList ID="cbxTypeOfService" runat="server" />
</td>
<th align="left">
Rule Number:
</th>
<td>
<igtxt:WebNumericEdit ID="neRuleNumber" runat="server" MaxValue="127"
MaxLength="3" SpinWrap="True" Width="50px" DataMode="Byte">
<SpinButtons Display="OnRight" />
</igtxt:WebNumericEdit>
</td>
</tr>
<tr>
<th align="left">
Rule Version:
</th>
<td>
<igtxt:WebNumericEdit ID="neRuleVersion" runat="server" MaxValue="127"
MaxLength="3" SpinWrap="True" width="50px" DataMode="Byte" >
<SpinButtons Display="OnRight" />
</igtxt:WebNumericEdit>
</td>
<th align="left">
Rule Priority:
</th>
<td>
<igtxt:WebNumericEdit ID="neRulePriority" runat="server" MaxValue="127"
MaxLength="3" SpinWrap="True" width="50px" DataMode="Byte">
<SpinButtons Display="OnRight" />
</igtxt:WebNumericEdit>
</td>
</tr>
<tr>
<th align="left" title="Effective date between date start and date end">
Effective Date Range:
</th>
<td>
<igsch:WebDateChooser ID="dtEffectiveDateStart" runat="server" Width="100px"
MinDate="1990-01-01" MaxDate="2099-12-31" NullDateLabel="" >
<CalendarLayout>
<CalendarStyle Font-Bold="False" Font-Italic="False" Font-Overline="False" Font-Strikeout="False" Font-Underline="False">
</CalendarStyle>
</CalendarLayout>
</igsch:WebDateChooser>
</td>
<th align="center">
-- and --
</th>
<td>
<igsch:WebDateChooser ID="dtEffectiveDateEnd" runat="server" Width="100px"
MinDate="1990-01-01" MaxDate="2099-12-31" NullDateLabel="" >
<CalendarLayout>
<CalendarStyle Font-Bold="False" Font-Italic="False" Font-Overline="False" Font-Strikeout="False" Font-Underline="False">
</CalendarStyle>
</CalendarLayout>
</igsch:WebDateChooser>
</td>
</tr>
<tr>
<th align="left" title="End date between date start and date end">
End Date Range:
</th>
<td>
<igsch:WebDateChooser ID="dtEndDateStart" runat="server" Width="100px"
MinDate="1990-01-01" MaxDate="2099-12-31" NullDateLabel="" >
<CalendarLayout>
<CalendarStyle Font-Bold="False" Font-Italic="False" Font-Overline="False" Font-Strikeout="False" Font-Underline="False">
</CalendarStyle>
</CalendarLayout>
</igsch:WebDateChooser>
</td>
<th align="center">
-- and --
</th>
<td>
<igsch:WebDateChooser ID="dtEndDateEnd" runat="server" Width="100px"
MinDate="1990-01-01" MaxDate="2099-12-31" NullDateLabel="" >
<CalendarLayout>
<CalendarStyle Font-Bold="False" Font-Italic="False" Font-Overline="False" Font-Strikeout="False" Font-Underline="False">
</CalendarStyle>
</CalendarLayout>
</igsch:WebDateChooser>
</td>
</tr>
<tr>
<th align="left" title="End date between date start and date end">
Age Range:
</th>
<td>
<igtxt:WebNumericEdit ID="neAgeStart" runat="server" MaxValue="120"
MaxLength="3" SpinWrap="True" width="50px" DataMode="Byte" >
<SpinButtons Display="OnRight" />
</igtxt:WebNumericEdit>
</td>
<th align="center">
-- and --
</th>
<td>
<igtxt:WebNumericEdit ID="neAgeEnd" runat="server" MaxValue="120"
MaxLength="3" SpinWrap="True" width="50px" DataMode="Byte" >
<SpinButtons Display="OnRight" />
</igtxt:WebNumericEdit>
</td>
</tr>
<tr>
<th align="left">
Use for Fee For Service?:
</th>
<td colspan="3">
<asp:DropDownList ID="cbxUseForFeeForService" runat="server"
DataTextField="TextField" DataValueField="ValueField">
<asp:ListItem Selected="True" Value="NA">Not Selected</asp:ListItem>
<asp:ListItem Value="N">No</asp:ListItem>
<asp:ListItem Value="Y">Yes</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
<tr>
<th align="left">
Use for Encounters?:
</th>
<td colspan="3">
<asp:DropDownList ID="cbxUseForEncounters" runat="server"
DataTextField="TextField" DataValueField="ValueField">
<asp:ListItem Selected="True" Value="NA">Not Selected</asp:ListItem>
<asp:ListItem Value="N">No</asp:ListItem>
<asp:ListItem Value="Y">Yes</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
<tr>
<th align="left">
Use For Gross Adjustments?:
</th>
<td colspan="3">
<asp:DropDownList ID="cbxUseForGrossAdjustments" runat="server"
DataTextField="TextField" DataValueField="ValueField">
<asp:ListItem Selected="True" Value="NA">Not Selected</asp:ListItem>
<asp:ListItem Value="N">No</asp:ListItem>
<asp:ListItem Value="Y">Yes</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
<tr>
<th align="left">
MSIS File:
</th>
<td colspan="3">
<asp:DropDownList ID="cbxMSISFile" runat="server"
DataTextField="TextField" DataValueField="ValueField">
<asp:ListItem Selected="True" Value="NA">Not Selected</asp:ListItem>
<asp:ListItem Value="ClaimIP">ClaimIP</asp:ListItem>
<asp:ListItem Value="ClaimLT">ClaimLT</asp:ListItem>
<asp:ListItem Value="ClaimOT">ClaimOT</asp:ListItem>
<asp:ListItem Value="ClaimRX">ClaimRX</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
</table>
</ContentTemplate>
</ajaxtk:TabPanel>
<ajaxtk:TabPanel runat="server" ID="tpCodeFields" HeaderText="&lt;span class='tabPanelSmall' title='Code Fields'&gt;Code Fields&lt;/span&gt;" ToolTip="Code Fields" >
<ContentTemplate>
<table border="0" width="720" cellspacing="0" cellpadding="0">
<tr>
<th align="left">
Diagnosis Code:
</th>
<td>
<asp:TextBox ID="txDiagnosisCode" runat="server" MaxLength="5" Columns="5"/>
</td>
<th align="left">
MCO Program:
</th>
<td>
<asp:TextBox ID="txMCOProgram" runat="server" MaxLength="4" Columns="4"/>
</td>
</tr>
<tr>
<th align="left">
Low Procedure Code:
</th>
<td>
<asp:TextBox ID="txLowProcedureCode" runat="server" MaxLength="6" Columns="6"/>
</td>
<th align="left">
High Procedure Code:
</th>
<td>
<asp:TextBox ID="txHighProcedureCode" runat="server" MaxLength="6" Columns="6"/>
</td>
</tr>
<tr>
<th align="left">
Provider Type:
</th>
<td>
<asp:TextBox ID="txProviderType" runat="server" MaxLength="4" Columns="4"/>
</td>
<th align="left">
Provider Type Specialty:
</th>
<td>
<asp:TextBox ID="txProviderTypeSpecialty" runat="server" MaxLength="4" Columns="4"/>
</td>
</tr>
<tr>
<th align="left">
Provider Type Sub Specialty:
</th>
<td colspan="3">
<asp:TextBox ID="txProviderTypeSubSpecialty" runat="server" MaxLength="4" Columns="4"/>
</td>
</tr>
</table>
</ContentTemplate>
</ajaxtk:TabPanel>
</ajaxtk:TabContainer>
<table border="0" width="720" cellspacing="0" cellpadding="0">
<tr>
<td colspan="4" align="center">
<br />
<asp:Button ID="btSearch" runat="server" Text="Search" />
<asp:Button ID="btCancel" runat="server" Text="Cancel" />
<asp:Button ID="btClear" runat="server" Text="Clear" />
</td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>

I have a number of Text Boxes, Combo Boxes and Infragistics controls within the two tabs.

I tried adding the meta tag:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />
but it didn't seem to help the problem.

Please advise.
Comments: Please upgrade to the latest version of AJAX Control Toolkit v15.1. If the problem remains, feel free to post a new issue.