AjaxControlToolkit - GridView wont select - don't understand viewstate - asp.net

Question

Overview:
I have two text boxes at the top of this form for inputting a beginning/ending date.
In the middle of the form I have a gridview that is populated with rows based on those dates.
At the bottom of the form I have a report generated based on which row is selected in the grid.
I selected the BeginningDate and the EndingDate and the gridview becomes populated (working). When I click the "Select" button on a row in the grid something is happening that makes it break. The row isn't selected. I know this because the CSS thats usually applied (by default) to a selected row in the gridview is not applied.
Additionally in the code-behind I'm setting...
lblGridError.Text = gridJobsReport.SelectedIndex.ToString()
The page load even has the same code, so the label reads "-1" when the page loads but never changes when I click the select buttons on the gridview. Something is breaking my Async postbacks. I wish I understood viewstate better, I'm always suspicious of it being the culprit but honestly I have no idea.
<%# Page Title="" Language="VB" MasterPageFile="~/Site.master" AutoEventWireup="false" CodeFile="BidReport.aspx.vb" Inherits="BidReport" %>
<%# Register assembly="Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" namespace="Microsoft.Reporting.WebForms" tagprefix="rsweb" %>
<asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" Runat="Server">
<ajaxToolkit:ToolkitScriptManager ID="tsmgrJobsReport" runat="server"
CombineScripts="True">
</ajaxToolkit:ToolkitScriptManager>
<p>
Enter a date range to populate the Jobs Grid.</p>
<asp:UpdatePanel ID="uPanelForm" runat="server">
<ContentTemplate>
<table>
<tr>
<td style="text-align: right">
<asp:Label ID="lblBeginningDate" runat="server" Text="Beginning Date:"></asp:Label></td>
<td>
<asp:TextBox ID="txtBeginningDate" runat="server" AutoPostBack="True"
CausesValidation="True"></asp:TextBox>
<ajaxToolkit:CalendarExtender ID="txtBeginningDate_CalendarExtender"
runat="server"
TargetControlID="txtBeginningDate">
</ajaxToolkit:CalendarExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="rfvBeginningdate" runat="server"
ControlToValidate="txtBeginningDate"
ErrorMessage="You must enter the Beginning Date" Font-Bold="True"
ForeColor="Red">*</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="revBeginningDate" runat="server"
ControlToValidate="txtBeginningDate"
ErrorMessage="Posted Date must be in the format "DD/MM/YYYY""
Font-Bold="True" ForeColor="Red"
ValidationExpression="^([1-9]|1[012])/([1-9]|[12][0-9]|3[01])/(20\d\d)$">*</asp:RegularExpressionValidator>
</td>
<td rowspan="2">
<asp:CompareValidator ID="cvBeginDateLTEndDate" runat="server"
ControlToCompare="txtEndingDate" ControlToValidate="txtBeginningDate"
ErrorMessage="Beginning Date must be earlier than the Ending Date."
Font-Bold="True" ForeColor="Red" Operator="LessThan">*</asp:CompareValidator>
</td>
</tr>
<tr>
<td style="text-align: right">
<asp:Label ID="lblEndingDate" runat="server" Text="Ending Date:"></asp:Label></td>
<td>
<asp:TextBox ID="txtEndingDate" runat="server" AutoPostBack="True"
CausesValidation="True"></asp:TextBox>
<ajaxToolkit:CalendarExtender ID="txtEndingDate_CalendarExtender"
runat="server" TargetControlID="txtEndingDate">
</ajaxToolkit:CalendarExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="rfvEndingDate" runat="server"
ControlToValidate="txtEndingDate"
ErrorMessage="You must enter the EndingDate Date" Font-Bold="True"
ForeColor="Red">*</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="revEndingDate" runat="server"
ControlToValidate="txtEndingDate"
ErrorMessage="Posted Date must be in the format "DD/MM/YYYY""
Font-Bold="True" ForeColor="Red"
ValidationExpression="^([1-9]|1[012])/([1-9]|[12][0-9]|3[01])/(20\d\d)$">*</asp:RegularExpressionValidator>
</td>
</tr>
</table>
<asp:ValidationSummary ID="valsumDates" runat="server" ForeColor="Red" />
<p>Click or Tap the "SELECT" button in the right column next to the Job you want and
a report will be generated below.</p>
<asp:GridView ID="gridJobsReport" runat="server" AutoGenerateColumns="False"
CellPadding="4" DataKeyNames="PostingID" DataSourceID="sqlDSReportGrid"
ForeColor="#333333" GridLines="Horizontal"
ShowHeaderWhenEmpty="True" Width="100%">
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
<Columns>
<asp:BoundField DataField="PostingID" HeaderText="PostingID" ReadOnly="True"
SortExpression="PostingID" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:BoundField DataField="Department" HeaderText="Department"
SortExpression="Department" />
<asp:BoundField DataField="JobName" HeaderText="JobName"
SortExpression="JobName" />
<asp:BoundField DataField="Shift" HeaderText="Shift" SortExpression="Shift" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:BoundField DataField="Needs" HeaderText="Needs"
SortExpression="Needs" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:BoundField DataField="PostedDate" HeaderText="PostedDate"
SortExpression="PostedDate" DataFormatString="{0:d}" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:BoundField DataField="PostedTime" HeaderText="Time"
SortExpression="PostedTime" DataFormatString="{0:t}" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:BoundField DataField="ClosingDate" HeaderText="ClosingDate"
SortExpression="ClosingDate" DataFormatString="{0:d}" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:BoundField DataField="ClosingTime" HeaderText="Time"
SortExpression="ClosingTime" DataFormatString="{0:t}" >
<ItemStyle HorizontalAlign="Center" />
</asp:BoundField>
<asp:CommandField ButtonType="Button" CausesValidation="True"
ShowSelectButton="true" />
</Columns>
<EditRowStyle BackColor="#999999" />
<EmptyDataRowStyle HorizontalAlign="Center" />
<EmptyDataTemplate>
There is currently no data to display based on the date range provided.
</EmptyDataTemplate>
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<SortedAscendingCellStyle BackColor="#E9E7E2" />
<SortedAscendingHeaderStyle BackColor="#506C8C" />
<SortedDescendingCellStyle BackColor="#FFFDF8" />
<SortedDescendingHeaderStyle BackColor="#6F8DAE" />
</asp:GridView>
<br />
<asp:Label ID="lblGridError" runat="server"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<ajaxToolkit:UpdatePanelAnimationExtender ID="uPanelForm_UpdatePanelAnimationExtender"
runat="server" TargetControlID="uPanelForm">
</ajaxToolkit:UpdatePanelAnimationExtender>
<p>You can print or save the report using the buttons at the top of the report.</p>
<asp:UpdatePanel ID="uPanelJobsReport" runat="server">
<ContentTemplate>
<rsweb:ReportViewer ID="rvJobsReport" runat="server" Width="100%">
</rsweb:ReportViewer>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="gridJobsReport"
EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
<asp:SqlDataSource ID="sqlDSReportGrid" runat="server"
ConnectionString="<%$ ConnectionStrings:JobsDB %>"
SelectCommand="SELECT dbo.tblJobPostings.PostingID, dbo.tblDepartments.Department, dbo.tblJobs.JobName,
dbo.tblJobPostings.Shift, dbo.tblJobPostings.Needs, dbo.tblJobPostings.PostedDate,
dbo.tblJobPostings.PostedTime, dbo.tblJobPostings.ClosingDate, dbo.tblJobPostings.ClosingTime
FROM dbo.tblJobPostings
INNER JOIN dbo.tblJobs ON dbo.tblJobPostings.JobID = dbo.tblJobs.JobID
INNER JOIN dbo.tblDepartments ON dbo.tblJobPostings.DeptID = dbo.tblDepartments.DeptID
WHERE dbo.tblJobPostings.ClosingDate >= #BeginningDate
AND dbo.tblJobPostings.ClosingDate <= #EndingDate
ORDER BY dbo.tblJobPostings.ClosingDate Asc">
<SelectParameters>
<asp:ControlParameter ControlID="txtBeginningDate" Name="BeginningDate"
PropertyName="Text" ConvertEmptyStringToNull="False" DefaultValue="" />
<asp:ControlParameter ControlID="txtEndingDate" Name="EndingDate"
PropertyName="Text" ConvertEmptyStringToNull="False" DefaultValue="" />
</SelectParameters>
</asp:SqlDataSource>
<asp:SqlDataSource ID="sqlDSJobReport" runat="server"></asp:SqlDataSource>
</asp:Content>

Answer 1

I really don't understand why this worked, but I decided to try handling the dates manually with session variables and its working perfectly now. It doesn't matter if I mess with the session state on the update panels or any of the form elements it seems to work no matter what now.
I guess that after the initial asyncpostback the sqldatasource wasn't reading the values in the textboxes, or something. If anyone can explain what was going on in another "Answer Question" section I'll accept it.
If Page.IsPostBack Then
Session("sBeginningDate") = txtBeginningDate.Text
Sessoin("sEndingDate") = txtEndingDate.Text
txtBeginningDate.Text = Session("sBeginningdate")
txtEndingDate.Text = Session("sEndingDate")
Else
Session("sBeginningDate") = Now().AddDays(-14)
Session("sEndingDate") = Now()
txtBeginningDate.Text = Session("sBeginningDate").ToShortDateString
txtEndingDate.Text = Session("sEndingDate").ToShortDateString
End If