fejl ved brug af ObjectDataSource

Hej

jeg får følgende fejl når jeg skal opdate en post i mit gridview:

ObjectDataSource 'ObjectDataSource1' kunne ikke finde en ikke-generisk metode 'cms_guestbook_update', der har parametrene: guestmessage, guestdate, guestname, guestmail, guestid

Min class ser ud som følgende:

Public Class ClassGuestbook
    Private _guestid As Integer
    Private _guestdate As DateTime
    Private _guestmessage As String
    Private _guestname As String
    Private _guestmail As String

    Public Property guestid() As Integer
        Get
            Return _guestid
        End Get
        Set(ByVal value As Integer)
            _guestid = value
        End Set
    End Property

    Public Property guestdate() As DateTime
        Get
            Return _guestdate
        End Get
        Set(ByVal value As DateTime)
            _guestdate = value
        End Set
    End Property

    Public Property guestmessage() As String
        Get
            Return _guestmessage
        End Get
        Set(ByVal value As String)
            _guestmessage = value
        End Set
    End Property

    Public Property guestname() As String
        Get
            Return _guestname
        End Get
        Set(ByVal value As String)
            _guestname = value
        End Set
    End Property

    Public Property guestmail() As String
        Get
            Return _guestmail
        End Get
        Set(ByVal value As String)
            _guestmail = value
        End Set
    End Property

    Public Function cms_guestbook_select() As DataTable
        Dim conn As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("StandardConn").ConnectionString)
        Dim da As SqlDataAdapter = New SqlDataAdapter("SELECT * FROM cms_guestbook ORDER by guestdate DESC", conn)
        Dim ds As DataSet = New DataSet()
        conn.Open()
        da.Fill(ds, "guestbook")
        conn.Close()
        Return ds.Tables("guestbook")
    End Function

    Public Function cms_guestbook_insert(ByVal guestname As String, ByVal guestmail As String, ByVal guestmessage As String)
        Dim guestdate As DateTime
        guestdate = DateTime.Now
        Dim conn As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("StandardConn").ConnectionString)
        Dim cmd As SqlCommand = New SqlCommand("cms_guestbook_insert", conn)
        cmd.CommandType = CommandType.StoredProcedure
        cmd.Parameters.Add(New SqlParameter("@guestdate", guestdate))
        cmd.Parameters.Add(New SqlParameter("@guestname", guestname))
        cmd.Parameters.Add(New SqlParameter("@guestmail", guestmail))
        cmd.Parameters.Add(New SqlParameter("@guestmessage", guestmessage))

        Dim result As Integer = 0
        conn.Open()
        result = cmd.ExecuteNonQuery()
        conn.Close()
        Return result
    End Function

    Public Function cms_guestbook_update(ByVal guestmessage As String, ByVal guestid As Integer)
        Dim conn As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("StandardConn").ConnectionString)
        Dim cmd As SqlCommand = New SqlCommand("cms_guestbook_update", conn)
        cmd.CommandType = CommandType.StoredProcedure
        cmd.Parameters.Add(New SqlParameter("@guestmessage", guestmessage))
        cmd.Parameters.Add(New SqlParameter("@GuestID", guestid))

        Dim result As Integer = 0
        conn.Open()
        result = cmd.ExecuteNonQuery()
        conn.Close()
        Return result
    End Function

    Public Function cms_guestbook_delete(ByVal guestid As Integer)
        Dim conn As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("StandardConn").ConnectionString)
        Dim cmd As SqlCommand = New SqlCommand("cms_guestbook_delete", conn)
        cmd.CommandType = CommandType.StoredProcedure
        cmd.Parameters.Add(New SqlParameter("@GuestID", guestid))

        Dim result As Integer = 0
        conn.Open()
        result = cmd.ExecuteNonQuery()
        conn.Close()
        Return result
    End Function
End Class


Gridview/ObjectDataSource ser ud som følgende:

        <asp:GridView ID="GridView1" runat="server" DataKeyNames="guestid" AllowPaging="True" DataSourceID="ObjectDataSource1">
            <Columns>
                <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
            </Columns>
        </asp:GridView>
        <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" DeleteMethod="cms_guestbook_delete"
            InsertMethod="cms_guestbook_insert" SelectMethod="cms_guestbook_select" TypeName="ClassGuestbook"
            UpdateMethod="cms_guestbook_update">
            <DeleteParameters>
                <asp:Parameter Name="guestid" Type="Int32" />
            </DeleteParameters>
            <UpdateParameters>
                <asp:Parameter Name="guestmessage" Type="String" />
                <asp:Parameter Name="guestid" Type="Int32" />
            </UpdateParameters>
            <InsertParameters>
                <asp:Parameter Name="guestname" Type="String" />
                <asp:Parameter Name="guestmail" Type="String" />
                <asp:Parameter Name="guestmessage" Type="String" />
            </InsertParameters>
        </asp:ObjectDataSource>