Fantastico will not install scripts
From Lunarpages Web Hosting Wiki
Q: Why won't Fantastico let me install a script on a client's account?
A: You must login with the client's login info rather than the Master Reseller info to use Fantastico on a client account. Also, since Fantastico scripts are database-driven, there must be a database available to use. You may have to adjust the number of databases provided in your package.