LinkButton in GridView does not fire RowCommand - ajax

Question

I am dynamically building a datatable and binding it to a gridview in a VB codebehind. I transform the gridview cell data into LinkButton controls to allow that data to be clicked for updates.
I am using AjaxControlToolkit to present a modal popup to collect data updates. Once those updates are completed, I rebuild the datatable and databind the gridview. In Gridview.RowCreated, I repeat the creation of the LinkButton controls on postback.
When the page is presented following an update, when I click on a LinkButton the postback happens but RowCommand is not fired. While debugging, I notice that when this occurs, Page.FindControl() cannot locate the targeted LinkButton control.
The page is returned without firing the RowCommand event to trigger the display of the modal popup. If I simply press the LinkButton a second time, the LinkButton control can be found using Page.FindControl() and RowCommand fires as desired.
What am I missing? Thanks much for any ideas to resolve this issue. I have struggled with this all day and I'm running out of ideas.
Thank you!
Here is requested code:
<asp:GridView ID="CustomeGridview" GridLines="Vertical" Width="100%" runat="server"
BackColor="White" BorderColor="#999999" BorderStyle="Solid" BorderWidth="1px"
CellPadding="3" AutoGenerateColumns="true" ForeColor="Black" ShowHeader="False" Font-Names="Verdana"
Font-Size="11px" OnRowCommand="CustomeGridview_RowCommand"
OnRowDataBound="CustomeGridview_RowDataBound">
<FooterStyle BackColor="#CCCCCC" />
<SelectedRowStyle BackColor="#000099" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
<HeaderStyle BackColor="Black" Font-Bold="True" ForeColor="White" />
<AlternatingRowStyle BackColor="#CCCCCC" />
</asp:GridView>
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Response.CacheControl = "no-cache"
Response.Expires = -1
Response.AddHeader("Pragma", "no-cache")
If Page.IsPostBack = False Then
ViewState("Left") = 3
ViewState("Right") = 6
generateManualDt()
Else
Dim controlName As String = Request.Params.Get("__EVENTTARGET")
Dim ctl As Control = Page.FindControl(controlName)
End If
Page_Header_Label.Text = "Action Qualification Matrix - " & Session("CurrentServiceName")
FormatColumns()
End Sub
Public Sub generateManualDt()
Dim ManualDt As DataTable = BuildMainDataTable()
ViewState("ManualDt") = ManualDt
CustomeGridview.DataSource = ManualDt
CustomeGridview.DataBind()
SetJumpScrollButtons()
End Sub
Protected Sub CustomeGridview_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles CustomeGridview.RowDataBound
Dim dt As DataTable = DirectCast(ViewState("ManualDt"), DataTable)
Dim dtsnocol As DataTable = DirectCast(ViewState("dtsnocol"), DataTable)
If e.Row.RowType = DataControlRowType.DataRow OrElse e.Row.RowType = DataControlRowType.Header Then
For gvCol As Integer = 7 To dt.Columns.Count - 1
e.Row.Cells(gvCol).Visible = False
Next
SetupGridRowControls(e, dtsnocol, dt)
End If
End Sub
Protected Sub CustomeGridview_RowCreated(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles CustomeGridview.RowCreated
Dim dt As DataTable = DirectCast(ViewState("ManualDt"), DataTable)
Dim dtsnocol As DataTable = DirectCast(ViewState("dtsnocol"), DataTable)
e.Row.Cells(0).Visible = False ' Hide the QuestionID column
If Page.IsPostBack Then
If e.Row.RowType = DataControlRowType.DataRow OrElse e.Row.RowType = DataControlRowType.Header Then
SetupGridRowControls(e, dtsnocol, dt)
End If
End If
End Sub
Private Sub SetupGridRowControls(ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs, ByRef dtsnocol As DataTable, ByRef mainDt As DataTable)
Dim CurrSnoCount As Integer = 0
If Not dtsnocol Is Nothing Then
CurrSnoCount = dtsnocol.Rows.Count
End If
If e.Row.DataItemIndex = 0 Then ' Scenario Number row
Dim snoLabel As New Label()
snoLabel.Text = "SCENARIO "
snoLabel.ID = "snoHdrLabel"
e.Row.Cells(2).Controls.Add(snoLabel)
Dim addScenarioBtn = buildAddButton("AddScenario", "", "Click to add a new scenario column")
e.Row.Cells(2).Controls.Add(addScenarioBtn)
ElseIf e.Row.DataItemIndex = 1 Then ' Question Header and Sno Descriptions
Dim questLabel As New Label()
questLabel.Text = "QUESTIONS "
questLabel.ID = "questdrLabel"
e.Row.Cells(2).Controls.Add(questLabel)
Dim addQuestionBtn = buildAddButton("AddQuestion", "", "Click to add a new question row")
e.Row.Cells(2).Controls.Add(addQuestionBtn)
Dim cellText As String = ""
Dim snoId As String = ""
For snoRowIdx As Integer = 0 To CurrSnoCount - 1
snoId = dtsnocol.Rows(snoRowIdx)("ScenarioID").ToString()
cellText = dtsnocol.Rows(snoRowIdx)("Note").ToString()
Dim lnkBtn = buildLinkButton("EditScenario", snoId, cellText)
e.Row.Cells(snoRowIdx + 3).Controls.Add(lnkBtn)
Next
ElseIf e.Row.DataItemIndex > 1 Then ' Question / Responses
Dim cellText As String = ""
Dim cellAddr As String = ""
Dim snoId As String = ""
Dim questId As String = mainDt.Rows(e.Row.DataItemIndex).Item(0).ToString.Trim
For snoRowIdx As Integer = 0 To CurrSnoCount - 1
snoId = dtsnocol.Rows(snoRowIdx)("ScenarioID").ToString.Trim
cellAddr = String.Format("{0}:{1}", questId, snoId)
cellText = mainDt.Rows(e.Row.DataItemIndex).Item(snoRowIdx + 3).ToString.Trim
Dim lnkBtn = buildLinkButton("EditResponses", cellAddr, cellText)
e.Row.Cells(snoRowIdx + 3).Controls.Add(lnkBtn)
Next
End If
End Sub
Private Function buildLinkButton(ByVal linkCmd As String, ByVal linkCmdArg As String, ByVal linkText As String) As LinkButton
Dim lnkBtn As New LinkButton()
lnkBtn.Text = linkText
lnkBtn.CommandName = linkCmd
lnkBtn.CommandArgument = linkCmdArg
lnkBtn.ToolTip = "Click to update"
lnkBtn.CssClass = "cell_link"
Return lnkBtn
End Function
Private Function buildAddButton(ByVal btnCmd As String, ByVal btnCmdArg As String, ByVal btnToolTip As String) As ImageButton
Dim imgBtn As New ImageButton()
imgBtn.CommandName = btnCmd
imgBtn.CommandArgument = btnCmdArg
imgBtn.ImageUrl = "~/Images/services/SmallAddBtn.gif"
imgBtn.ToolTip = btnToolTip
imgBtn.ID = String.Format("{0}_GenImageButton", btnCmd)
Return imgBtn
End Function