Foreign language works in one server, doesn’t work in another

I have installed WP several times, so I’m not a newbie, but now I have encountered very odd problem with certain server.

When I’m trying to install WordPress with foreign language support, it doesn’t work: have tested Finnish, Swedish and German now. No matter how much I try, WP keeps installing itself in English, even if the “wp-config.php”-language configuration is correct and proper mo-files were installed in the respective subfolder.

However, when I copy the SAME installation files to ANOTHER server (just changing the wp-config SQL-information), WP will immediately install smoothly in Finnish, Swedish and German. Just the way it should do and just the way it has always done.

I tested this several times with different WP versions, having always the same result. Foreign language support works nicely in one server, but in another one it does not.

I know that the server configuration shouldn’t have any effect on Foreign Language support, but this does not seem to be the case in my case.

Just wonder if anybody has met the same problem, and how did they solve it. Because identical files work in one server but don’t work in another, it has to be something with the server itself…

All the best,
Tapio