Several users have reported that calendars that are part of their Google Apps directed domains show empty calendars or missing events. Google Apps domains have more specific controls than those in an non-Apps account:
Go into your domain management for a google apps account (not the 'account settings-dashboard' area, but actual domain management),
Go to Settings, and THERE, you can set a calendar control to its highest level. Changing it to 'show details but don't allow changes' will allow all activity to be displayed on the calendar.