Ok,
Could someone else please test his multilanguage site..
You can check with your admin user.
So if you have for example EN and DE language, if your prefered admin language is EN, when you log in, you will see pages in EN. When you switch language to DE, when you open home page, you will see pages on DE (so far this is ok)
Now if you change your prefered admin language to any other than these 2 (which frontend pages use) your site will show under construction page to this user until he log of, or change language..
Someone please confirm this, so I can post a ticket..
cheers
UPDATE: It happens when Page languages are enabled in Advanced Settings