Translate Blogs MU

Hi team!
I'm working on translating the theme "Blogs MU" developed by SH Mohanjith.

I made a copy of the file en_EN.po that I renamed fr_FR.po.
Then, I translated each line in the language file that I recorded.
I've uploaded these two files in "/wp-content/themes/blogs-mu/languages/" and I checked in "wp-config.php" that was good for WPLANG value as "fr_FR" ... but the translation is not taken into account :disappointed:

I checked the load_theme_textdomain in the functions.php file that is configured with the value blogs-mu:
define( 'TEMPLATE_DOMAIN', 'blogs-mu' );
load_theme_textdomain( TEMPLATE_DOMAIN, TEMPLATEPATH . '/ languages ??/' );

Can you tell me what step I forgot please?