Getting duplicated entity metadata from somewhere : ?

For some reason, my order entity metadata is being duplicated, resulting in array type values instead of strings (which in turn causes WSODs when entity_metadata_list_extract_type() hits these properties). Here's the resulting property array for order_id, and the same holds true for order_number.

                    [order_id] => Array
                        (
                            [label] => Array
                                (
                                    [0] => Order ID
                                    [1] => Order ID
                                )

                            [description] => Array
                                (
                                    [0] => The internal numeric ID of the order.
                                    [1] => The unique ID of the order.
                                )

                            [type] => Array
                                (
                                    [0] => integer
                                    [1] => integer
                                )

                            [query callback] => entity_metadata_table_query
                        )

The definition in commerce_order.info.inc is:

  $properties['order_id'] = array(
    'label' => t('Order ID'),
    'description' => t('The internal numeric ID of the order.'),
    'type' => 'integer',
  );

However, I also noticed in the dump that the full schema is being converted to entity metadata properties for things I haven't defined yet in my .info.inc. What's interesting, though, is that this same duplication problem isn't affecting uid which is also defined in my .info.inc.

Any leads?