Roles and permissions

Thanks.
The confusion gets worse. This is how I had my Moodle set up. I thought it wasn't working because when I tried to enroll on some courses I could not. I have however just discovered that any courses that were set up with 'Is this a meta course?:' set to Yes it won't allow enrollments, it comes up with this course does not allow public access. All the other courses are fine i.e. the ones set to is it Meta No!
I now need to find a quick way of identifying all the courses set up as meta courses so that when we upgrade across the board I can turn them to no.

As for checking the Hide box when assigning a role where exactly is the hide box? I went to the course, clicked assign roles, no check box there, clicked on tutor, I can see the existing tutors and the potential but no check boxes for anything. I tried from the participants block, no hides there, from the settings block, no hides there. Even at site level and users I still cannot find any boxes to check for hide.
Thanks