attributes not work for new language pack

my site had two languages, i installed the third language pack today and i get an issue

if i switch to english or another old language, go to admin->catalog->option name manager, the options display correctly,
but if i switch to the new language, there's no option there, only after i add a new option, it owuld be shown, but it doesn't show the options that i added before installing this language pack

even if i switch to english, then edit the current options, after i save it, only the languages of options which added before the new language pack installed are saved, the new language options are keep empty even after i click on the save button.

i'm not sure what i missed, cause when i installed my first language pack, everything goes well, but this time, when i install this new language pack, i can't get the attributes work right,

any help?

i found that not only attributes but also other functions don't work on this new language

i tried editing the product name and description, after i saved the modification, the names and descriptions of the other old languages are saved, but the name and description of this new language keep empty

what's wrong with this new language pack? i installed it just as usual, i'm not sure what i missed

er... what's the language (pack) in question?

problem solved !!
i thought about it again, oh i had skiped one step when i installed this language pack, i didn't go to admin to add the language, but went to phpmyadmin to add the language to the zen_language table, now i know that is not a correct method

i thought that adding language from admin is just affect the zen_language table, it seems it is not just add records to zen_language table ?