Public Sub Load(ByVal Filename As String)
        Dim ret = My.Settings.Setting1
        Dim Delimiter() As String = {"%EOL%" & vbCrLf}
        Dim Objects() As String = My.Computer.FileSystem.ReadAllText( _
          Filename).Split(Delimiter, StringSplitOptions.RemoveEmptyEntries)
 
        For Each Property_ As System.Configuration.SettingsPropertyValue In _
          My.Settings.PropertyValues
            For Each Item As String In Objects
                Dim itemParts() As String = Split(Item, "=", 2)
                If itemParts.Length = 2 Then
                    If Property_.Name = itemParts(0) Then
                        Property_.PropertyValue = DeserializeObject(itemParts( _
                          1), Property_.PropertyValue.GetType())
                    End If
                End If
            Next
        Next
    End Sub
 
    Public Sub Save(ByVal Filename As String)
        Dim ret = My.Settings.Setting1
        Dim FileContent As String = String.Empty
        For Each item As System.Configuration.SettingsPropertyValue In _
          My.Settings.PropertyValues
            FileContent &= item.Name & "=" & SerializeObject( _
            item.PropertyValue, item.PropertyValue.GetType) & "%EOL%" & vbCrLf
        Next
        My.Computer.FileSystem.WriteAllText(Filename, FileContent, False)
    End Sub
 
    Private Function SerializeObject(ByVal obj As Object, ByVal type As _
      System.Type) As String
        Dim sb As New System.Text.StringBuilder()
        Dim myStream As New System.IO.StringWriter(sb)
        Dim xmlSer As New System.Xml.Serialization.XmlSerializer(type)
        xmlSer.Serialize(myStream, obj)
        SerializeObject = sb.ToString
        myStream.Close()
    End Function
 
    Private Function DeserializeObject(ByVal xmlString As String, ByVal Type As _
      System.Type) As Object
        Dim xmlSer As New System.Xml.Serialization.XmlSerializer(Type)
        Dim myStream As New System.IO.StringReader(xmlString)
        Return xmlSer.Deserialize(myStream)
        myStream.Close()
    End Function

Danke, an ALLE !!