Set the Tabcontrols SizeMode to Fixed.
Change the TabControls ItemSize property so that it gets serialized.
Change the TabControls DrawMode to OwnerDrawFixed
Then add the following code (assuming your tabcontrol is called TabControl1)
\\\
Private Sub TabControl1_DrawItem(ByVal sender As System.Object, _
           ByVal e As DrawItemEventArgs) Handles TabControl1.DrawItem

   e.Graphics.FillRectangle(SystemBrushes.Control, e.Bounds)
   Dim sf As New StringFormat
   sf.Alignment = StringAlignment.Center
   sf.LineAlignment = StringAlignment.Center
   e.Graphics.DrawString(TabControl1.TabPages(e.Index).Text, _
           TabControl1.Font, SystemBrushes.ControlText, _
           RectangleF.op_Implicit(e.Bounds), sf)
End Sub
///

For some more TabControl tips visit my site:
http://dotnetrix.co.uk/tabcontrols.html