As a note, I am not using HotTrack - I turned this both on and off and had
the same issues either way.

Bob

When using a BackgroundImage property the painting is very slow.
The TabControl does not support Transparent Background and AFAIK this is not
going to be addressed, although Visual Styled TabControls do appear to have
a Transparent Background.

You'll find a TabControl on my downloads page that does support Transparent
Background, but does not support XP Visual Styles. It also supports one or
two other frequently requested features.
http://dotnetrix.co.uk/download/TabControlEX.dll

If all you want is to ease the flicker then add the following code to your
form:
\\\
'Modify Sub New as follows
Public Sub New()
   MyBase.New()

   'This call is required by the Windows Form Designer.
   InitializeComponent()
   'Add any initialization after the InitializeComponent() call
   setstyle(ControlStyles.AllPaintingInWmPaint Or _
               ControlStyles.DoubleBuffer Or _
               ControlStyles.ResizeRedraw Or _
               ControlStyles.UserPaint, True)
End Sub

'and add this code to the form
Private BackImage As Bitmap

Private Sub MainForm_Load(ByVal sender As System.Object, _
           ByVal e As System.EventArgs) Handles MyBase.Load
   If Not BackgroundImage Is Nothing Then
       BackImage = New Bitmap(Me.BackgroundImage)
       Me.BackgroundImage = Nothing
   End If
End Sub

Protected Overrides Sub OnPaintBackground(ByVal pevent As _
           System.Windows.Forms.PaintEventArgs)
   If BackImage Is Nothing Then
       MyBase.OnPaintBackground(pevent)
   Else
       pevent.Graphics.DrawImage(BackImage, Point.Empty)
   End If
End Sub
///