Ya probaste con éste evento:
Cita: Private Sub TabControl1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TabControl1.SelectedIndexChanged
Dim iIndex as Integer = TabControl1.SelectedIndex
Select case iIndex
case 0:
'hacer algo
case 1:
'otra cosa
End Select
End Sub
O que es exactamente lo que necesitas..??
