primary links and menu_primary_menu

Work flow to reproduce problem

a) clean 4.7.3 install plus internationalization module (4.7)
b) enable clean urls
c) settings.php have menu_primary_menu in $conf['i18n_variables'] (simply copied the 4.7 example from the internationalization documentation/handbook)
d) enable i18n modules
e) confirm internationalization is working ok for other things such as site_name
f) problem is that same primary links appear for both languages

settings.php

$conf['i18n_variables'] = array(
// Site configuration
'site_name',
'site_slogan',
'site_mission',
'site_footer',
'anonymous',
// Node help
'blog_help',
'story_help',
// User configuration
'user_registration_help',
'user_mail_welcome_subject',
'user_mail_welcome_body',
'user_mail_approval_subject',
'user_mail_approval_body',
'user_mail_pass_subject',
'user_mail_pass_body',
// Theme settings: you may want to use different logos for each language
'theme_settings',
// These are for primary and secondary links
'menu_primary_menu',
'menu_secondary_menu',
);

My attempts to fix/understand the problem:

Investigating if there are additionational variables that should be overriden such as primary_links.
phptemplate engine uses 'primary_links' => menu_primary_links() for it's assignment, that menu_primary_links, which returns a variable called $links not menu_primary_menu, but does use variable_get (menu_primary_menu)

My mysql variable table has menu_primary_menu | s:1:"2";