cakephp .po files not being used

cakephp .po files not being used

I'm trying to get CakePHP's i18n component to work. I have extracted my
strings to app/Locale/default.pot using the i18n console task. I then
copied it into app/Locale/eng/LC_MESSAGES/default.po and
app/Locale/fra/LC_MESSAGES/default.po making sure to change the extension.
I used the program Virtaal (similar to Poedit) to translate some of the
strings.
In my app/Config/core.php I have set my default language to english with
Configure::write('Config.language', 'eng'); if I change it to
Configure::write('Config.language', 'fra'); I expected to see the new
translated strings but nothing changed. I tried setting the
Config.language key in the session as well but it didn't do anything.
Printing out the configure value and session values I can see they are
being set.
Am I missing something here? also in the many different posts I've been
reading about i18n in CakePHP I've seen the key fre being used
interchangeably with fra is there a difference?