Tag display problem~~

[reporter]

thanks for reading~ when I add a tag like 'C++' to an article sometimes it didn't display right.....it is C%uFF0B%uFF0B ～～I add chinese it also can't display rightit seem like %u5988%u5988I enter 2 same words and it is display 2 %u5988~so it is might be some encode problemand it display right when I add tag in the admin panel~ the same problem happen when I add Categories~I add chinese thought categories but at this time chinese characters is display as ????~ I check the database I found the tag store in the database is same with this worry displayso i think it has something worry before store them in the database~sometimes the tag display right but never the thought the categories.... the data display isn't right too~may is display as 五月.......why..... and I think there must some encoding problem when i add tag in the front page and categories~but I can't found which function is used for get the user input and store them in the database please help me~thank you very much~

ps: i am not a native english speaker...so sorry for my bad english......