if system language is set in a different langage than the application, language mismatch

Hello Febrice,

This problem is related to translation.
Due to the missing translation in .po file, it takes OpenERP Default language.
So, You need to update the code or rectify the problem in .po files.

Thanks.

Fabrice,

When using the GTK client, the client application cannot currently change the language for the menus and buttons dynamically, because these are loaded automatically by the GTK framework when the application is initialized.
Normally the language of the GTK menus and buttons will be changed after the client is restarted, using the application language of the last user that logged in into the system (basically the "lang" value of the [client] section in the config file, usually in $HOME/.openerprc)

There might be some limitations on some systems where the GTK client is not able to switch to the OpenERP language for menus and buttons if that language is not available in the local settings of the operating system (i.e. if it is not an available locale). In that case there will be a warning message in the GTK log file when it starts.

If you have tried this technique and the language is still not correctly set, please reopen the bug report and explain the different things you tried, what are the locales available on your machine, and possibly the error messages that are in the GTK logfile (or console)

In the Web client the issue is a bit different because all menus and buttons are part of the web pages, so they can be directly translated.

I hope this helps...