I need help with iTunesU maximum number of enrolled students

I am an administrator of a school iTunesU site and have many instructors affiliated with the school. Recently courses created by affiliated instructors that have in the past been able to have an unlimited number of enrolled students have been getting messages that they have 'reached the maximum number of enrolled students' and auto-enrolment has been turned off.

Our school uses iTunesU heavily and has many courses with 100's of students enrolled. I was wondering if this could be a recent bug that will be fixed, or if it's a new iTunesU policy?

Many thanks,

Mike