Very useful and valuable tip. Thanks for sharing that information. Better than all of us finding out the hard way.
Could you answer a related question for me? Is it a reasonable thing to do to have a file folder on the Mac internal HD with Time Machine used inside of it, for quick recovery and accessability (since it really isn't intended to be a backup program per se) and then have an external drive that is for the exclusive purpose of having a reliable backup disk? OR Is it smarter to spend the extra $$ and get TWO external drives; one dedicated to Time Machine and one to the backup program?