iCloud returning the response: "...is not a location that supports this request." when adding calendar item
On the desktop version of iCal I can take a Reminder and drag it into the Calendar to turn it into a task with time associated with it (e.g. "Take the car to the repair shop" reminder gets turned into "Take the car to the repair shop" event at, say, 2pm on Friday). When iCal tries to sync the event to iCloud, however, it returns an error, saying that "....is not a location that supports this request.". You can either then choose to Go Offline or Revert to Server. The odd thing is that the event AND the Reminder both appear to stay where I placed them, even though I click "Revert to Server". So what's being reverted? It doesn't appear that the event is being deleted....
My main concern is that I decide to ignore the warning dialogs, "Reverting to Server" each time, and then one day, poof! there goes all the events.
Importantly: The events that I supposedly created from the Reminders don't show up in the iCloud view of the Calendar. So it seems that they are at least "reverted" at the server level . Even with a manual refresh on my Mac, iCal doesn't seem to get rid of these "reverted" calendar events.
Ideas as to what's being not supported?
iCal-OTHER, Mac OS X (10.7.2)