Module controls are little tools that appear in the top bars of modules, such as the login module. The controls allow a user to modify the layout he sees for the Tiki by moving the modules up and down, from the left column to the right, or vice-versa, or even removing the module entirely.
To activate modules controls in your Tiki you need to complete several steps:
Login as admin
make sure "Show Module Controls" is active.
make sure "Users can Configure Modules" is active.
make sure "Display modules to all groups always" is active.
In tiki-assignpermission.php make sure your users have tiki_p_configure_modules