Ok, I have updated JMS and it works now.
But now there is a big SECURITY PROBLEM
If the new user is superadmin, he is able to install components (if the slavesite is created with copying folders).
That means, if he is installing e. g. the extplorer (
http://extplorer.sourceforge.net/) he has access to all files in the mastersite directory.
If he is installing e. g. joommyadmin (
http://joomlacode.org/gf/project/joommyadmin/frs/?action=FrsReleaseBrowse&frs_package_id=3762) he can read all data of the database.
Is it possible, to put the superadmin from the mastersite in the new slavesite as superadmin and the new admin (from user) as normal admin?
Best regards
Muskes