Cannot display different language encode

I have recentely found firefoxportable and found this really helpful but found a problem.

when i am running firefoxportable on a computer without admin right, and without language pack installed on the computer, if i run firefoxportable to visit some other language web site ( chinese for example ) i am not able to change the encode to display the web page in that language even tho i have the options to such a language and all i got are a bunch of uni-code characters.

when i try the same app on a different computer with language pack installed i am able to use firefoxportable to display the language correctely.

is there anywayz to work arround this? the major idea for portable apps is to have firefox running on computer which have no admin rights to installing anything right?