Thanks for asking. There wasn't any particular error (i.e., Error 550: xyuwhatever) ... I followed the instructions and started my first backup. Everything went smoothly for a minute as the bar crept up 50%, 55%, etc ... so I went to get something to eat.
When I came back ... the browser had the WELCOME TO WORDPRESS FAMOUS 5 MINUTE Install" screen.
I was like ... "What the hell???"
And I couldn't get off of it. Not through the wp-admin, not even straight to my domain. I thought I lost 6 months of work.
On the backup site itself, it registered 0% backed up! Yes, Jason ... I freaked.
So while I was cursing the guys who made this software and trying to get to my files through the FTP and salvage what I could ... my site just came back up. Like nothing happened.
I have yet to attempt that again. Not looking to risk it twice.