Funny permission problems

[Alexander Windbichler]

Hello,

I'm using MySQL 4.0.21 on a Debian machine. If I create a new user and a new database, all is working perfect. The user has no global rights, excepting "USAGE".
I create a new database called user_db_username_1. The user can only access this database - it works.
If the user trys to create a database (for example) "test123" it won't work, but if he creates a database like "user?db?username?1" it works without a problem. This only works, if he replaces the "_" signs throw special characters like ?,$,%,&, ...

The user has no permission to do this, but it works. Does anybody know, whats wrong? I have no solution.

thanks for your help,
alex