[RESOLVED] Graphics wont stick

[Bulldog]

I want to put an outline around each control on a panel, as a test case I used some checkboxes. It draws the outlines fine, but if I mouseover the checkboxes, they dont repaint. I cant see anything wrong with this (or I might have code blindness). Can anyone see what's wrong?

Declare Function GetDesktopWindow Lib "user32" Alias "GetDesktopWindow" () As Integer
    Declare Function GetWindowDC Lib "user32" Alias "GetWindowDC" (ByVal hwnd As Integer) As Integer
    Dim MyPanel As New Panel
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim d As IntPtr = New IntPtr(GetWindowDC(MyPanel.Handle.ToInt32))
        Dim g As Graphics = Graphics.FromHdc(d)
        PaintCon(MyPanel, g)
        g.Dispose()
    End Sub
    Private Sub PaintCon(ByVal Con As Control, ByVal g As Graphics)
        For Each ctl As Control In Con.Controls
            If ctl.Controls.Count > 0 Then
                PaintCon(ctl, g)
            Else
                If ctl.GetType.ToString.ToLower = "system.windows.forms.checkbox" Then
                    Dim ConRect As New Rectangle(MyPanel.PointToClient(ctl.Parent.PointToScreen(ctl.Location)), ctl.Size)
                    g.DrawRectangle(Pens.Black, ConRect)
                    RemoveHandler Con.Paint, AddressOf ConPaint
                    AddHandler Con.Paint, AddressOf ConPaint
                End If
            End If
        Next
    End Sub
    Private Sub ConPaint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs)
        Dim con As Control = DirectCast(sender, Control)
        Dim ConRect As New Rectangle(MyPanel.PointToClient(con.Parent.PointToScreen(con.Location)), con.Size)
        e.Graphics.DrawRectangle(Pens.Black, ConRect)
    End Sub