I've searched and tried every "fix" I've found on the internet to no avail. Time Machine keeps giving me the error "Unable to complete backup. An error occurred while creating the backup folder." I'm using an external USB 2.0 drive. I've reformatted the drive, I've repaired it, and I've added the drive to the "privacy" setting for finder since some people claimed that was the problem. I've done everything I can find on internet searches. Another important note is that whenever this happens, I'm unable to eject the drive normally. If I restart, it seems like the first backup runs fine. At this point I THINK this is related to the machine going to sleep during a backup. I've read that that is a problem too and if I've got a process running (hadbrake encodes) the backup will run multiple times in a row without error. But as soon as that process completes the next backup fails. If this is the case this is a major bug for crying out loud. How can I set my machine to never go to sleep at this point (Mac Mini running latest version of SL) so I can at least test. And if this ends up being the case, shame on Apple for such a blatant bug!