I apologize for the poor grammar in the title, but it seemed funny. I was recently backing up a 250GB NTFS drive (IDE in USB enclosure) to my 500GB HFS+ drive (SATA in USB enclosure) since my friend wanted to reformat the 250 into HFS+ (couldn't get NTFS3G MacFUSE to work) and didn't want to lose his data. I decided to use Carbon Copy Cloner to perform the copy since I am familiar with the software, and wanted to avoid any pesky "This file cannot be copied because" crap. I was planning on running the copy overnight, and the last thing I wanted was to wake up 8 hours later only to find that after 15 minutes of copying it had encountered something like that. Well, Carbon Copy Cloner is cloning, and its copying, and I guess it is carbon... but whatever. About halfway through the copy, my MacBook threw up a "You are out of disk space" notification, on my internal System Drive! Somehow, someway, i lost 15GB of space in about 5 minutes. So I went through my drive and started deleting things that I figured I didn't need anymore anyway, and that space disappeared as well. Figuring that it had something to do with the Copy process, I force quit that and restarted my machine (This has happened to me in the past, I was running the CS3 beta and it had some sort of weird issue that it ate all my free space. A restart would correct the issue, and removing CS3 stopped it from happening) The problem was that upon restart my space was still gone. I was sitting at a whopping 104MB of free space. Earlier that day I had 16GB of free space! So I ran WhatSize to see where this file is that is eating all my free space (I figured that it was some sort of weird caching thing for the copying process) and it returned that it found 58.3GB of files, except I am using 75.65GB of space... so where's my Gigs At? By the way, I confirmed WhatSize's information with OmniDiskSweeper. Anyone have any suggestions besides backing up and reformatting?