FAF doesn't "know" where localisation files are !

Manimal_

Everytime I launch FAF, my FA v1.6.6 (Steam) is turned to English language, while it was initialy in my native language.

The problem :
FAF has changed my game.prefs for an incorrect language !
Open AppData\Local\Gas Powered Games\Supreme Commander Forged Alliance\Game.prefs and take a look at :

the field language = 'us',
the field selectedlanguage = 'us',

while these should be set on my country code...

Also, FAF is ignoring where to access the good old localised audio folder and files :

When I set it to some language, the Tutos won't play given they're in english because the engine is "lost in translation"..
FAF is set to english by default and doesn't set for us the proper localisation.

Last but not least :
I noticed that the visual parts of the speeches aka videos were hugely accelerated with no audio. (like 5 times faster)
IMHO this means the XACT Audio engine is one of the main cause of FA's slowdowns...

Manimal_

More about this issue :

I've noticed by verifying "AppData\Local\Gas Powered Games\Supreme Commander Forged Alliance\Game.prefs" that the voice volume was OFF, while it was at MAX in the Options window in-game :

options = {
    (...)
    vo_volume = 0,
    (...)
},

The localized voices are still muted in spite of my attempts to :

set the volume to the MAX from the Options window in-game.
click on [Apply].
click on [OK].

I've even thought I had to quit the game and launch it again after this change, to no avail.

I've openned game.prefs with NP++ and noticed the value was still vo_volume = 0,.
So I've changed it for vo_volume = 100,, but it's had no effect at all.

FA v1.6.6 's localized voices are definitely like "broken" since I installed FAF, even by running the game without FAF.

Help will be much appreciated.