Always, always, always press the save button frequently with Adobe Captivate. Ask yourself how much work are you willing to lose. Your answer to that question is how frequently you should press the same button. For me that's about every fifteen minutes or so.
Also, consider doing a save as with today's date as an amendment at least once per day to cover yourself when the stakeholder says "Remember that thing you had in the course five days ago? Yeah can you put that back in"