[whpalmer4]

The repeating task stuff only creates a new task when an existing task is marked complete. The mere passage of time will not cause another task to be created. If you are seeing something appear out of thin air, without any action on your part, you've simply reached the start date for that action and were in a view where actions which have not yet reached their start date are not shown (showing Available or Next Actions, for example, or Completed). When you mark an item complete, the repeat policy for that item is checked and a new one created if appropriate.

It is worth noting that if you accidentally complete a repeating item and decide you want to undo that action, but rather than use the File->Undo command, you just uncheck it, you will get a duplicate item. This happens because toggling the checkmark does not remove the item created when a repeating item is marked complete. Better to use File->Undo (or cmd-Z) than to repeatedly click the checkbox to avoid such issues.