It's hard to say exactly. It depends of how is configured your database. If the username field is, say, 20 chars long, and the db server uses "raw" UTF-8 (I mean, using the long notation
Java uses, instead of writing only the 6 chars and handling it internally), then much probably you'll have problems.
However, if in fact this is the problem, there should be a remedy, otherwise which logic would be that if you had to design a database for latin languages and other for cyrililc ones?!
As far as I know, JForum as some expressive number of users from Russia, Japan, China and other places where cyrillic chars are used, and, at least they tried JForum just once and never more, the login and all other stuff must work - so that's why I guess there is some issue with the database configuration.
Rafael
[originally posted on jforum.net by Rafael Steil]