Module causes themes to become disabled

We run a large website on a multi-tier server environment behind a load balancer. A team of editors use the back-end to manage the site. But over the past few weeks we had errors that where thrown such as:

Duplicate entry 'sites/all/themes/mythemenamehere/style.css' for key 1 query: INSERT INTO system (name, description, type, filename, status, throttle, bootstrap) VALUES ('mythemenamehere', 'sites/all/themes/mythemenamehere/page.tpl.php', 'theme', 'sites/all/themes/mythemenamehere/style.css', 0, 0, 0) in /data/web/een/includes/database.mysql.inc on line 175.

After a lot of code digging I found that the taxonomy_theme module caused this problem. In the method _taxonomy_theme_options() in the taxonomy_theme_admin.inc file the module uses system_theme_data() to get a list of all themes. This is very bad practice because this method does a lot of database queries and updates which cause concurrency problems when used by to many users.

Instead the method list_themes() should be used to get a list of theme names. This is much faster and doesn't have an effect on the Drupal core inner workings.

so:

/**
 * function _taxonomy_theme_options().
 * (create a list of available themes)
 */
function _taxonomy_theme_options($admin_themes = FALSE, $default = TRUE) {
  $themes = system_theme_data();
  $options_themes = array();

Should become:

/**
 * function _taxonomy_theme_options().
 * (create a list of available themes)
 */
function _taxonomy_theme_options($admin_themes = FALSE, $default = TRUE) {
  $themes = list_themes();
  asort($themes);
  $options_themes = array();

I hope this helps other users in the future.