This is a browser dependent bug. I tested this with the latest stable multilingual version of PMA using Chrome 21.0.1180.89 and Firefox 15.0. In both the multilingual version of phpMyAdmin will start in Arabic. In Firefox when I change to another language it will breafly do so but then second it will change back to Arabic, making it utterly useless when you don't know that language. In chrome it works fine.
A quick solution is to blame the browser, but still it would be nice when someone with more time can get to the bottom of this.