How do I translate eNewsletter?

Hello!

I have translated your eNewsletter plugin to finnish and its workin ok in my single Wordpress install. But I want to use this same language file in my Wordpress Multisite... I have placed language file from single install to plugins language folder and my config.php has "fi_FI" as a language but it doenst work... Am i missing something or is this handled differently in WP Multisite?