Mq translate plugin custom post type issue

MQtranslate is a fork of Qtranslate so the hooks should be the same, and to get Qtranslate to Work in custom taxonomies I use this:

/**
 * qtranslate custom taxonomies
 */
function qtranslate_edit_custom_taxonomies(){
  $args=array(
    'public' => true ,
    '_builtin' => false
  );
  $output="object"; // or objects
  $operator="and"; // 'and' or 'or'

  $taxonomies = get_taxonomies($args,$output,$operator);

  if  ($taxonomies) {
    foreach ($taxonomies  as $taxonomy ) {
      add_action( $taxonomy->name.'_add_form', 'qtrans_modifyTermFormFor');
      add_action( $taxonomy->name.'_edit_form', 'qtrans_modifyTermFormFor');
    }
  }
}
add_action('admin_init', 'qtranslate_edit_custom_taxonomies');

this should work for you as well.