[Plugin: xLanguage] Cant login to admin panel

ok, i’ve found solutions (in manual 😉 …i know, i know rtfm, rtfm :/ )

Because I was using other language than English inside the admin panel (languages dir: pl_PL.mo, pl_PL.po), i had to change their names like xlanguage’s lang’s name settings (pl.mo, pl.po), and in wp-config.php
define ('WPLANG', 'pl');