hola lobo tienes que poner keyascii=0 para que no lo mueste el caracter
Private Sub txtNombre_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtNombre.KeyPress
Dim KeyAscii As Short = CShort(Asc(e.KeyChar))
If KeyAscii = 13 Then ' Enter
Me.PcbNom_Click(sender, e)
If Me.ListBox1.Items.Count > 0 Then
Me.ListBox1.Focus()
Me.ListBox1.SelectedIndex = 0
End If
End If
If KeyAscii = 39 Then
keyascii=0
End If
End Sub