Security and privacy

As for giving teachers the ability to enroll their students, I want this capability also.  When using Moodle 1.9 this was not a problem.  I had it set up, however, when I updated to 2.1, I seem to have lost this ability.  I have tried everything suggested and it still does not work.  I have set a new role and it still does not work.  Can anyone direct me to a document that will help me with this, thanks