I've just successfully upgraded from 154 to 156c.

Noticed however i was getting -


at the bottom of some Customer Address / Billing Address details both in Admin -> Orders Details, Invoice etc and also on the Order Confirmation Emails.

It is my belief the following line of code is missing from the function zen_address_format in /zencart/includes/functions/functions_customers.php -

$address['telephone'] = !empty($incoming['telephone']) ? zen_output_string_protected($incoming['telephone']) : '';