Erro ao mudar de pagina em um GridView

Prezados,

Tenho uma página aspx com um grid e os dados são conctados via a sub BindData, pois o banco access possui senha e não foi possível colocar um acessdatasource.

Tudo está funcionando normalmente até que o usuário clique para mudar de página no grid ou que tente efetuar um postback. Quando então, ele não executa a atualização para a página solicitada e uma mensagem no erro do browser informa:

/applications/core/interface/imageproxy/imageproxy.php?img=http://www.tvtsistemas.com.br/erro.png&key=8dda86b5a26b5906bca2abd1c4d4780c7065df1277f70c2ba706107f353a7373" alt="Imagem Postada" />

Seguem os códigos:

Imports System.Data
Imports System.Data.OleDb
Partial Class BioLista
Inherits System.Web.UI.Page
Sub BindData()
'1. Cria a conexao
Dim myConnection As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=~\dados\Banco.mdb;Jet OLEDB:Database Password=123456;"
Dim cn As OleDbConnection = New OleDbConnection(myConnection)

'2. Cria o objeto command passando a string SQL

 Const strSQL As String = "SELECT * FROM ListaReg"
 Dim myCommand As New OleDbCommand(strSQL, cn)

 '3. Cria o objeto DataAdapter
 Dim myDA As New OleDbDataAdapter()
 myDA.SelectCommand = myCommand

 '4. Preenche o DataSet
 Dim myDS As New DataSet()
 myDA.Fill(myDS)

 'Define a fonte de dados do datagrid
 GridView1.DataSource = myDS
 GridView1.DataBind()
	End Sub
	Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
 If Not IsPostBack Then
 BindData()
 End If
	End Sub
	Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
 If e.Row.RowType = DataControlRowType.DataRow Then
 Dim img As Image = CType(e.Row.FindControl("AlertaImg"), Image)
 If (e.Row.Cells(8).Text) <> "" Then
 If (e.Row.Cells(8).Text) = "Ativo" Then
 img.ImageUrl = "~/img/Debito.gif"
 img.Visible = True
 img.ToolTip = "Débito"
 Else
 img.ImageUrl = "~/img/credito.gif"
 img.Visible = True
 img.ToolTip = ""
 End If
 Else
 img.ImageUrl = "~/img/Credito.gif"
 img.ToolTip = ""
 img.Visible = True
 End If
 End If
	End Sub

End Class

<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">

 <ContentTemplate>
 <fieldset>
 <table cellspacing="0" cellpadding="6" align="Center" rules="all" border="1" id="GridBusca1" style="color:#333333;width:100%;border-collapse:collapse; background-color:#dbeaf5">
 <tr>
 <td align="center">Registro:</td>
 <td align="left"><asp:TextBox ID="Registro" runat="server" CssClass="lbl" Width="70px" MaxLength="10"></asp:TextBox></td>
 <td align="center">CPF:</td>
 <td align="left"><asp:TextBox ID="Cpf" runat="server" CssClass="lbl" Width="70px" MaxLength="11"></asp:TextBox></td>
 <td align="center">Nome:</td>
 <td align="left"><asp:TextBox ID="Nome" runat="server" CssClass="lbl" Width="150px" MaxLength="255"></asp:TextBox></td>
 <td align="center">Inscritos:</td>
 <td align="left"><asp:TextBox ID="Inicio" runat="server" CssClass="lbl" Width="70px" MaxLength="10"></asp:TextBox>
 <cc1:MaskedEditExtender ID="Inicio_MaskedEditExtender" runat="server"
 CultureAMPMPlaceholder="" CultureCurrencySymbolPlaceholder=""
 CultureDateFormat="" CultureDatePlaceholder="" CultureDecimalPlaceholder=""
 CultureThousandsPlaceholder="" CultureTimePlaceholder="" Enabled="True"
 TargetControlID="Inicio"
 Mask="99/99/9999"
 MaskType="DateTime"
 AcceptAMPM="False">
 </cc1:MaskedEditExtender> | 
 <asp:TextBox ID="Final" runat="server" CssClass="lbl" Width="70px" MaxLength="10"></asp:TextBox>
 <cc1:MaskedEditExtender ID="Final_MaskedEditExtender" runat="server"
 CultureAMPMPlaceholder="" CultureCurrencySymbolPlaceholder=""
 CultureDateFormat="" CultureDatePlaceholder="" CultureDecimalPlaceholder=""
 CultureThousandsPlaceholder="" CultureTimePlaceholder="" Enabled="True"
 TargetControlID="Final"
 Mask="99/99/9999"
 MaskType="DateTime"
 AcceptAMPM="False">
 </cc1:MaskedEditExtender></td>

 <td align="center">Situação:</td>
 <td align="left"><asp:DropDownList ID="Situacao" runat="server" CssClass="def">
 <asp:ListItem>Todos</asp:ListItem>
 <asp:ListItem Value="1">Normal</asp:ListItem>
 <asp:ListItem Value="2">Atrasados</asp:ListItem>
 <asp:ListItem Value="3">Cancelados</asp:ListItem>
 <asp:ListItem Value="11" Selected="True">Atr+Canc</asp:ListItem>
 </asp:DropDownList>
 </td>
 <td align="left"><asp:ImageButton ID="Button1" runat="server" ImageUrl="~/img/busca.gif" ToolTip="Pesquisar" /></td>
 </tr>
 </table>
 <asp:UpdateProgress ID="UpdateProgress1" runat="server" AssociatedUpdatePanelID="UpdatePanel1" DisplayAfter="0">
 <ProgressTemplate>
 <br />
 <table align="center" cellspacing="0" cellpadding="0" border="1" style="width:300px;border-color:#B3C9DE;background-color:#F1F2F6">
 <tr>
 <td align="center" style="width:300px;">
 <table align="center" cellspacing="0" cellpadding="6">
 <tr>
 <td align="center" style="width:20px;"><asp:Image ID="progAjaxImg" runat="server" ImageUrl="img/progAjax2.gif" /></td>
 <td align="left">Pesquisando. Aguarde...</td>
 <td><input id="Button2" type="button" value="x" onclick="CancelAsyncPostBack()" style="font-size: 7pt; font-family: 'Trebuchet MS, Verdana'; font-weight: bold;height:20px" /></td>
 </tr>
 </table>
 </td>
 </tr>
 </table><br />
 </ProgressTemplate>
 </asp:UpdateProgress>

 <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"
 AutoGenerateColumns="False" CellPadding="4"
 ForeColor="#333333" PageSize="25" Width="100%">
 <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
 <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
 <Columns>

 <asp:TemplateField HeaderStyle-Width="14px" ItemStyle-HorizontalAlign="Center" HeaderText="S" SortExpression="Img">
 <ItemTemplate>
 <asp:Image ID="AlertaImg" runat="server"/>
 </ItemTemplate>
 <HeaderStyle Width="14px" />
 <ItemStyle HorizontalAlign="Center" />
 </asp:TemplateField>
 <asp:TemplateField ControlStyle-Width="16px" HeaderStyle-Width="16px">
 <ItemTemplate>
 <asp:HyperLink ID="LinkInfo" runat="server" ToolTip="Clique para verificar ou registrar as ações" NavigateUrl='<%# "Registro.Aspx?i=" & Eval("Registro")%>' ImageUrl="img/info.gif"></asp:HyperLink>
 </ItemTemplate>
 <ControlStyle Width="16px" />
 <HeaderStyle Width="16px" />
 </asp:TemplateField>
 <asp:BoundField DataField="Registro" HeaderText="Registro"
 SortExpression="Registro" ItemStyle-HorizontalAlign="right" >
 <ItemStyle HorizontalAlign="Right" />
 </asp:BoundField>
 <asp:BoundField DataField="Nome" HeaderText="Nome" SortExpression="Nome"
 ItemStyle-HorizontalAlign="left" >
 <ItemStyle HorizontalAlign="Left" />
 </asp:BoundField>
 <asp:BoundField DataField="CPF" HeaderText="CPF" SortExpression="CPF"
 ItemStyle-HorizontalAlign="Center" >
 <ItemStyle HorizontalAlign="Center" />
 </asp:BoundField>
 <asp:BoundField DataField="Modo" HeaderText="Modo" SortExpression="Modo"
 ItemStyle-HorizontalAlign="Left" >
 <ItemStyle HorizontalAlign="Left" />
 </asp:BoundField>
 <asp:BoundField DataField="DataRegistro" HeaderText="Registrado Em"
 SortExpression="DataRegistro" ItemStyle-HorizontalAlign="Center"
 DataFormatString="{0:dd/MM/yyyy}" >
 <ItemStyle HorizontalAlign="Center" />
 </asp:BoundField>
 <asp:BoundField DataField="Situacao" HeaderText="Situacao"
 SortExpression="Situacao" ItemStyle-HorizontalAlign="Left" >
 <ItemStyle HorizontalAlign="Left" />
 </asp:BoundField>
 <asp:BoundField DataField="DA" HeaderText="DA" SortExpression="DA" ItemStyle-HorizontalAlign="Center" />
 </Columns>
 <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
 <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
 <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
 <EditRowStyle BackColor="#999999" />
 <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
 </asp:GridView>
 </fieldset>
 </ContentTemplate>
 </asp:UpdatePanel>

Desde já muito obrigado!