I have a problem with firefox while using xlanguage.

Using:
XOOPS 2.0.16
xlanguage 3.0.1
firefox 2.0.0.3

I installed two base languages, and I choose one of them as default in XOOPS config. When I open this page first time with IE, it loads my default language. But when I tried same with Firefox it always displays English as default language. I should change the language one time, then it is ok until cookie expires. Than I need to set the language again.

Any idea?

it is not related to XOOPS or xlanguage.
xlanguage always recognize your local language in the browser.

you should add your language in firefox via Tools --> Options --> Advanced - languages