This may or may not be related, but using Outlook 2013 and iOS 7 connected to an account with ActiveSync, reminders on calendar events never fire. A user can send an invite and set a reminder notification when creating the invite, but at some point the reminder becomes deactivated before it is supposed to fire (15 minutes before event, in most cases), and never fires in Outlook. When you open the event in Outlook, the reminder is disabled as though it were never sent.