Bad argument in "subproducts_variations_overview"

Hi,

In the "subproducts_variations_overview" function, you may replace this code

<?php
function subproducts_variations_overview() {
  $ptypes = subproducts_variations_product_types();
  $ptype = arg(4) ? arg(4) : current($ptypes);
?>

by this one

<?php
function subproducts_variations_overview() {
  $ptypes = subproducts_variations_product_types();
  $ptype = arg(3) ? arg(3) : current($ptypes);
?>

to get the good argument passed on the drupal path

keep the good work.