Did you attend the user group "Everyone"? You have to deny this group the permission to add events to the calendar.
Thanks for your reply Black Rider, I think so.. Usergroups > Everyone > Calendar > all disabled / no permissions. lol. I can't see anything though, regarding Events for the calender though either. I tried looking all over in usergroups and other areas in ACP about Events.. but didn't see anything referencing "Events" lol.