RadGrid doesn't export data, and erases command item bar

    <telerik:RadGrid ID="rgPickedDetail" runat="server" AllowFilteringByColumn="False" AllowPaging="True" OnItemCommand="rgPickedDetail_ItemCommand"
        AllowSorting="True" DataSourceID="DetailDataSource" ShowStatusBar="True" PageSize="15" OnItemDataBound="rgPickedDetail_ItemDataBound"
        Skin="Telerik" AllowAutomaticUpdates="true" AutoGenerateColumns="False">
        <ExportSettings HideStructureColumns="true" Excel-Format="Xlsx" ExportOnlyData="true" IgnorePaging="true" />
        <PagerStyle Mode="NextPrevNumericAndAdvanced"></PagerStyle>
        <MasterTableView CommandItemDisplay="Top" HierarchyLoadMode="ServerOnDemand" AllowSorting="false" AutoGenerateColumns="false">
            <CommandItemSettings ShowExportToCsvButton="true" ShowExportToExcelButton="true" ShowAddNewRecordButton="false" ShowRefreshButton="true" />
            <Columns>
                <telerik:GridBoundColumn DataField="Plant" DataType="System.String" HeaderText="Plant" ReadOnly="True" UniqueName="Plant" />
                <telerik:GridBoundColumn DataField="PartNum" DataType="System.String" HeaderText="Part" ReadOnly="True" UniqueName="PartNum" />
                <telerik:GridBoundColumn DataField="SerialNum" DataType="System.String" HeaderText="Serial number" ReadOnly="True" UniqueName="SerialNum" />
                <telerik:GridBoundColumn DataField="QtyPicked" DataType="System.Int32" HeaderText="Picked" ReadOnly="True" UniqueName="QtyPicked" />
                <telerik:GridBoundColumn DataField="QtyReq" DataType="System.Int32" HeaderText="Requested" ReadOnly="True" UniqueName="QtyReq" />
                <telerik:GridBoundColumn DataField="Scanned" DataType="System.DateTime" DataFormatString="{0:M/d/yy HH:mm}" HeaderText="Scanned" ReadOnly="True" UniqueName="Scanned" />
                <telerik:GridBoundColumn DataField="FromLoc" DataType="System.String" HeaderText="From" ReadOnly="True" UniqueName="FromLoc" />
                <telerik:GridBoundColumn DataField="ToLoc" DataType="System.String" HeaderText="To" ReadOnly="True" UniqueName="ToLoc" />
                <telerik:GridBoundColumn DataField="Picked" DataType="System.Boolean" Display="false" HeaderText="Picked (invisible)" UniqueName="Picked" />
            </Columns>
        </MasterTableView>
    </telerik:RadGrid>

    Shared ReportDate As Date

    Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
        If ReportDate = Nothing Then
            ReportDate = Today
            StartDate.SelectedDate = ReportDate
        End If
        SetReportDate()

        If Not Page.IsPostBack Then
        End If
    End Sub

    Protected Sub MessageBox(msg As String)
        ScriptManager.RegisterStartupScript(Me, Me.GetType, "WindowsScript", "alert('" + msg + "');", True)
    End Sub

    Protected Sub rgPickedDetail_ItemDataBound(sender As Object, e As GridItemEventArgs)
        If e.Item.GetType() Is GetType(GridDataItem) Then
            Dim item As GridDataItem = e.Item
            item.ForeColor = IIf(item("Picked").Text = "True", Color.Green, Color.Red)
        End If
    End Sub

    Protected Sub StartDate_SelectedDateChanged(sender As Object, e As Calendar.SelectedDateChangedEventArgs)
        ReportDate = e.NewDate
        SetReportDate()
        rgPickedSummary.Rebind()
        rgPickedDetail.Rebind()
    End Sub

    Private Sub SetReportDate()
        SummaryDataSource.SelectParameters("StartDate").DefaultValue = ReportDate
        DetailDataSource.SelectParameters("StartDate").DefaultValue = ReportDate
    End Sub

    Protected Sub rgPickedDetail_ItemCommand(sender As Object, e As GridCommandEventArgs)
        If e.CommandName = "ExportToExcel" Then
            rgPickedDetail.Rebind()
        End If
    End Sub

    Protected Sub rgPickedDetail_ItemCreated(sender As Object, e As GridItemEventArgs) Handles rgPickedDetail.ItemCreated
        If TypeOf e.Item Is GridCommandItem Then
            ScriptManager.GetCurrent(Page).RegisterPostBackControl(e.Item.FindControl("ExportToExcelButton"))
        End If
    End Sub

    Protected Sub rgPickedSummary_ItemCreated(sender As Object, e As GridItemEventArgs) Handles rgPickedSummary.ItemCreated
        If TypeOf e.Item Is GridCommandItem Then
            ScriptManager.GetCurrent(Page).RegisterPostBackControl(e.Item.FindControl("ExportToExcelButton"))
        End If
    End Sub