PowerShell - Problema con la altura de un cuadro de lista

Add-Type -AssemblyName System.Windows.Forms

Add-Type -AssemblyName System.Drawing

$form = New-Object System.Windows.Forms.Form

$form.Text = 'Grupos del Servicio'

$form.Size = New-Object System.Drawing.Size(500,400)

$form.StartPosition = 'CenterScreen'

$OKButton = New-Object System.Windows.Forms.Button

$OKButton.Location = New-Object System.Drawing.Point(75,320)

$OKButton.Size = New-Object System.Drawing.Size(75,23)

$OKButton.Text = 'OK'

$OKButton.DialogResult = [System.Windows.Forms.DialogResult]::OK

$form.AcceptButton = $OKButton

$form.Controls.Add($OKButton)

$CancelButton = New-Object System.Windows.Forms.Button

$CancelButton.Location = New-Object System.Drawing.Point(150,320)

$CancelButton.Size = New-Object System.Drawing.Size(75,23)

$CancelButton.Text = 'Cancel'

$CancelButton.DialogResult = [System.Windows.Forms.DialogResult]::Cancel

$form.CancelButton = $CancelButton

$form.Controls.Add($CancelButton)

$label = New-Object System.Windows.Forms.Label

$label.Location = New-Object System.Drawing.Point(10,20)

$label.Size = New-Object System.Drawing.Size(280,20)

$label.Text = 'Selecciona los grupos que desees'

$form.Controls.Add($label)

$listBox = New-Object System.Windows.Forms.Listbox

$listBox.Location = New-Object System.Drawing.Point(10,40)

$listBox.Size = New-Object System.Drawing.Size(100,100)

$listBox.SelectionMode = 'MultiExtended'

[void] $listBox.Items.Add('Item 1')

[void] $listBox.Items.Add('Item 2')

[void] $listBox.Items.Add('Item 3')

[void] $listBox.Items.Add('Item 4')

[void] $listBox.Items.Add('Item 5')

[void] $listBox.Items.Add('Item 6')

[void] $listBox.Items.Add('Item 7')

[void] $listBox.Items.Add('Item 8')

[void] $listBox.Items.Add('Item 9')

[void] $listBox.Items.Add('Item 10')

[void] $listBox.Items.Add('Item 11')

[void] $listBox.Items.Add('Item 12')

[void] $listBox.Items.Add('Item 13')

$listBox.Height = 70

$form.Controls.Add($listBox)

$form.Topmost = $true

$result = $form.ShowDialog()

if ($result -eq [System.Windows.Forms.DialogResult]::OK)

{

    $x = $listBox.SelectedItems

    $x

}