Language bug on different computers

[Kverkagambo]

I installed Roundcube for a client with latvian language interface. Everything was fine, I tested on different browsers.
But then client sent me an email that says that interface is still in English, and a screenshot that proves it. So, on his computer ( IE8 ) all Roundcube labels has set to defaults, except for page title.
What could be wrong?

[rosali]

The default language is automatically detected based on the language the browser sends to the web server (List of HTTP headers - Wikipedia, the free encyclopedia). So if the browser does not send a latvian language header you can not expect that the interface automatically shows latvian labels. The user has to adjust his language preference in the settings section.

[SKaero]

You can also set thedefault language by setting the $rcmail_config['language'] in the /config/main.inc.php

[Kverkagambo]

Ok, thanks.