Hi,
Analysing internal Calendar code brings to the following conclusion :
If an event is automatically generated, it should have its "modulename" set that allows the Calendar to get additional metadata for it.
The issue is that this chain produces an edit and a delete link on the event instance (when displayed in calendar, say in the "upcoming events" page), that update and delete THE ACTIVITY MODULE itself.
This is not suitable for instance in scheduler (see previous post on critical bug on Scheduler), where the event is marking an appointement. We should as max delete the appointment generating the event, or at least only the event record.
I can do the latter avoiding telling the calendar my module name (the calendar will default giving a local edit/delete possibility on the calendar event only). Is it a so clean way ?
If not : there is a structure issue on what can be given to the calendar to allow the source of the event. Such feature seems being event dangerous.
I'll confirm this architecture issue in tracker.