I'm sorry, but you will have to explain the issue a bit more. It really isn't clear.
You say you've "prepared a registration," but what kind of registration? You mean some kind of form in Flash?
And then you say "in the database," but what database? Is flash sending that information to some kind of database? If so what method are you using and what kind of database is it?
And then you ask about a unicode conversion. Flash is most happy when using Unicode, so in general all the text should already be in Unicode. So there might be something wrong with how the database server is recieving the information.
And finally the only thing I know is that if you are using useCodePage, you shouldn't.