After upgrade to Apex 4.2 it seems that I've problem with translated application. My situation is:
Primary language is "Italian", application language is derived from browser. Translated application in english.
Using Internet Explorer 8.0, english version but language preference is set to only "Italian (Italy) [it]", the application is displayed fully not translated (italian) but BROWSER_LANGUAGE item is = 'en'.
If in IE language preference I add also "English [en-US]" together with "Italian (Italy) [it]" (doesn't matter the order), all labels of application remain not translated, but a field which value is derived from APEX_LANG.MESSAGE is translated into english.
Same behaviour with Firefox 17 in linux. Application is fully italian if "intl.accept_language" = "it", but if I add "en" ("it,en") application is displayed almost fully not translated in italian, but the field derived from APEX_LANG.MESSAGE is translated in to english. And BROWSER_LANGUAGE item is always = 'en' too.
So how does APEX detect and decide the language to use, in case of "derived from browser"?
Is it a bug, or what?