Don't understand where to call MyBase.Paint

Using Windows Forms, .NET 1.1, VS 2003

I understand that you call the base class method in vb.net to do some initializing or setting things up normally before you call your derived method but I am missing something from my understanding
I inherited from a datagridtextboxcolumn and override the paint method to color cells depending on their value etc. The problem I am having is deciding where to call the base paint method as I don't think I really understand.

If I call the paint method in one place, then some cells get colored while others don't, or the formatting gets messed up in one place and not in others. Below is my paint method. I initially got the code online and modified it to do what I want. Basically, I have been calling MyBase.Paint() at different points in my code to get it working but I don't know why. Help.


 Protected Overloads Overrides Sub Paint(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal source As CurrencyManager, ByVal rowNum As Integer, ByVal backBrush As Brush, ByVal foreBrush As Brush, ByVal alignToRight As Boolean)

    Dim e As DataGridFormatCellEventArgs
    e = New DataGridFormatCellEventArgs(rowNum, Me._col, Me.DataGridTableStyle.DataGrid.Font, backBrush, foreBrush)
    RaiseEvent SetCellFormat(Me, e)

    'Note that UseBaseClassDrawing is the property of useBaseClassDrawing private data member
    'It is set to false by default
    If e.UseBaseClassDrawing Then
        MyBase.Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight)
    Else
        g.FillRectangle(e.BackBrush, bounds)
        g.DrawString(Me.GetColumnValueAtRow(source, rowNum).ToString, e.TextFont, e.ForeBrush, bounds.X, bounds.Y)
    End If

    If (e.TextFont Is Me.DataGridTableStyle.DataGrid.Font) = False Then
        e.TextFont.Dispose()
    End If

    Try
        'If the cell value is 0 or less than 0, color it red
        Dim cellVal As String = Me.GetColumnValueAtRow(source, rowNum)
        If (Not cellVal Is Nothing) Then
            Dim c As Integer
            c = CType(cellVal, Integer)
            If (c = 1 Or c < 1) Then
                e.ForeBrush = New SolidBrush(Color.Red)

                MyBase.Paint(g, bounds, source, rowNum, backBrush, e.ForeBrush, alignToRight)
            Else
                MyBase.Paint(g, bounds, source, rowNum, backBrush, e.ForeBrush, alignToRight)
            End If
        End If


        'Check for the cell date value and if less than now, draw lines in the cell
        cellDate = Me.DataGridTableStyle.DataGrid.Item(rowNum, 0)
        If (Not hourMinString Is Nothing) Then
            Dim cellToDisable As Boolean = CellDateLessToday(cellDate, DateTime.Now())
            If (cellToDisable = True) And (_col = 1) Then
                DrawLinesInCell(g, bounds)
            Else
                MyBase.Paint(g, bounds, source, rowNum, e.BackBrush, e.ForeBrush, alignToRight)
            End If
        End If

        'Change the background of the grids to blue to indicate the cell that was
        'clicked in the mousedown event
        If (Me.DataGridTableStyle.DataGrid.CurrentRowIndex = rowNum)_
            And (Me.DataGridTableStyle.DataGrid.CurrentCell.ColumnNumber = _col) And _
            ((rowNum <> 0) And (Me._col <> 0)) Then
            If (cellToDisable = False Or _col <> 1) Then
                e.BackBrush = New SolidBrush(Color.Blue)
                e.ForeBrush = New SolidBrush(Color.White)
                g.FillRectangle(e.BackBrush, bounds)
                'Make the font bigger in the clicked cell
                e.TextFont = New Font("Arial", 24, FontStyle.Bold)
                Dim intX As Integer = bounds.X + (bounds.Width / 3)
                Dim intY As Integer = bounds.Y + (bounds.Height / 4)
                g.DrawString(Me.GetColumnValueAtRow(source, rowNum).ToString, e.TextFont, e.ForeBrush, intX, intY)
                'MyBase.Paint(g, bounds, source, rowNum, e.BackBrush, e.ForeBrush, alignToRight)
            End If
        End If

        'MyBase.Paint(g, bounds, source, rowNum, e.BackBrush, e.ForeBrush, alignToRight)
    Catch ex As Exception
        'Empty catch
    Finally
        'make sure the base class gets called to do the drawing with the possibly
        'changed brushes
        'MyBase.Paint(g, bounds, source, rowNum, e.BackBrush, e.ForeBrush, alignToRight)
    End Try
    'MyBase.Paint(g, bounds, source, rowNum, e.BackBrush, e.ForeBrush, alignToRight)
End Sub