VS 2008 - BorderStyle Changed To None When Maximizing Form

I have a normal form (FormBorderStyle = Sizeable). When the user maximizes the form, the form's border should disappear and fully cover the screen. Like so:

vb
Private Sub frmVideo_SizeChanged(ByVal sender As Object,
ByVal e As System.EventArgs) Handles Me.SizeChanged
If Me.WindowState = FormWindowState.Maximized Then
'Remove border
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.None
'Bring to front
Me.TopMost = True
End If
End Sub

Problem is, when the form gets maximized and border changed to None, the form doesn't cover the whole screen. The form gets the same height as when it is maximized with a titlebar on top. So, the form is about 20 pixels too short, leaving most of the Windows taskbar uncovered. So, apparently, if the FormBorderStyle changes after the form has maximized, the change in size is not corrected. How do I change a form's size when it's maximized or how do I change the FormBorderStyle before maximization is finished?