ec_anon max() warning

Just downloaded the latest dev to work on ec_nodeaccess, and I just let whatever dependencies turn on automatically (the dependencies I had set on my module are ec_product and ec_store)
I keep seeing this error everywhere:

warning: max() [function.max]: Array must contain at least one element in /home/braksato/public_html/drupal6/sites/all/modules/ecommerce/ec_anon/ec_anon.module on line 172.

For your reference here is the code with the call to the max() function:

<?php

/**
 * Implementation of hook_customer_info_alter().
 *
 * Make sure that the anonymous customer type is always last.
 */
function ec_anon_customer_info_alter(&$types) {
  $weights = array_map('_ec_customer_get_weights', $types);
  unset($weights['anonymous']);
  
  $types['anonymous']->weight = max($weights)+1;
}

?>

Have I got the wrong dependencies, some stale data, or is this a bug?