I really hope someone will be able to help me as I have posted this problem on many forums (french forums) without any answers.
I'm french and installed the french version of WordPress 3.4.1. I also use a french theme. 99% of the time, my page loads in french (which is good). However, sometimes, for no reason, it loads in english (which is obviously the default language).
The Website: http://www.sorcieresdufjord.com
Here are some thoughts and things I tried:
1) Already checked WPLANG and it is set to "fr_FR". Downloaded my entire website folder. Opened ALL the files, searched for all instances of "define(WPLANG" with Notepad++, all of them are ok.
2) All the PO and MO files are "fr_FR" (both in wordpress and my theme)
3) When the page render in english rather than in french, the Dashboard is ALSO in english.
4) I tried deleting or renaming existing en_US PO and MO files.
5) I emptied my browser cache, history or everything.
6) Got this problem on IE8, IE9, Chrome, Firefox and Safari
7) No translation plugin installed
8) All other plugins are native-english so I hard-translated them in french (I know this is mean...)
9) Recompiled my PO files in MO (or the inverse...?) with POEdit
10) The problems seems to happen when I load my page the first time. But sometimes, it just get in english while working in the dashboard.
11) I use jQuery on the vast majority of my pages.
I Guess there is still a lot to try but for now, I'm completely overwhelmed!
Thanks in advance for all your help and have a nice day! :-)