I am baffled that nobody has replied to this thread with expert or developer insight. I ran 7 pass, which went through the night - and now it is starting over. It 'created a second temporary file' and now is on pass 2 - again! In addition, chrome will not launch. I was able to launch safari, which then (now) stopped doing anything. I am using an older macbook (10.8.5). Someone please help! My computer has been acting funny just in the past week or two - when i 'click' things, for example, sometimes it 'sticks' and I drag around what I clicked rather than opening it. And when typing, once or twice the cursor got lost and started adding letters in the middle of the line .. I've been using ccleaner to keep things tidy and that has generally worked fine, but this problem has persisted so I opted to wipe free space. But - why is it making the passes a second time??