Version : Moodle 2.3.2+ (Build: 20121014)
+ Access into a course
+ Create a course event in the calendar
+ Go to course administration and start a backup proccess
+ If you uncheck Include enrolled users, when you try to select Include calendar events is disabled, so events are not considered in backup (else you can check or uncheck calendar events)
I think that course events must be independent of enrolled users (like our previous version Moodle 1.8.10)
Anyone of you with the same problem?